arch/x86/ebda: Change memcpy() to endian wrappers

Change memcpy()s and memset()s to endian.h wrappers for consistency
and safety. Add zero_n() wrapper to safely clear memory.

Change-Id: If155d82608c81992f05eae4d2223de6f506e98c5
Signed-off-by: Ryan Salsamendi <rsalsamendi@hotmail.com>
Reviewed-on: https://review.coreboot.org/20240
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed