soc/amd/common: Add amdblocks/spi.h

Add the spi header for spi function prototypes. Fixes spi.c build
error for the missing header.

Change-Id: I0dbb5bf84cc3462a7aa58a5531d6b8b8bc8ca4df
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: https://review.coreboot.org/22793
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
2 files changed