CVE-2026-31561 x86/cpu: Remove X86_CR4_FRED from the CR4 pinned bits mask

In the Linux kernel, the following vulnerability has been resolved: x86/cpu: Remove X86CR4FRED from the CR4 pinned bits mask Commit in Fixes added the FRED CR4 bit to the CR4 pinned bits mask so that whenever something else modifies CR4, that bit remains set. Which in itself is a perfectly fine...