x86/microcode/AMD: Check microcode container data in the late loader

Convert the late loading path to use the newly introduced microcode
container data checking functions as it was previously done for the
early loader.

[ bp: Keep header length addition in install_equiv_cpu_table() and rediff. ]

Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20181107170218.7596-14-bp@alien8.de