drm/amd/display: fix mapping to non-allocated address

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/gpu/drm/amd/display/dc/gpio/dcn20/hw_factory_dcn20.c",
                        "drivers/gpu/drm/amd/display/dc/gpio/dcn30/hw_factory_dcn30.c",
                        "drivers/gpu/drm/amd/display/dc/gpio/dcn32/hw_factory_dcn32.c",
                        "drivers/gpu/drm/amd/display/dc/gpio/ddc_regs.h"
                    ],
                    "versions": [
                        {
                            "version": "4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c",
                            "lessThan": "8ce8a443ddd9002861a4ee8a7e33a0c02717422f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c",
                            "lessThan": "24aaf6603600d6d1159973c809ea2737664b28c4",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c",
                            "lessThan": "9190d4a263264eabf715f5fc1827da45e3fdc247",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                }

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/gpu/drm/amd/display/dc/gpio/dcn20/hw_factory_dcn20.c",
                        "drivers/gpu/drm/amd/display/dc/gpio/dcn30/hw_factory_dcn30.c",
                        "drivers/gpu/drm/amd/display/dc/gpio/dcn32/hw_factory_dcn32.c",
                        "drivers/gpu/drm/amd/display/dc/gpio/ddc_regs.h"
                    ],
                    "versions": [
                        {
                            "version": "4.15",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.15",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.16",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.2.3",
                            "lessThanOrEqual": "6.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }