CVE-2026-46156 LoongArch: Fix potential ADE in loongson_gpu_fixup_dma_hang()

In the Linux kernel, the following vulnerability has been resolved: LoongArch: Fix potential ADE in loongsongpufixupdmahang The switch case in loongsongpufixupdmahang may not DC2 or DC3, and readlcrtcreg will access with random address, because the "device" is from "base+PCIDEVICEID", "base" is...