x86, microcode, AMD: Add a reusable buffer
x86, microcode, AMD: Add a reusable buffer

Add a simple 4K page which gets allocated on driver init and freed on
driver exit instead of vmalloc'ing small buffers for each ucode patch.

Signed-off-by: Borislav Petkov <2b4cb5acba6b5321acd37371d9b73a646c388783@amd.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs