A stack overrun has been observed on AMD64 CPUs during the SMM module
relocation process. Change the assumed required size from equaling the
save structure's size to a Kconfig symbol.
A value of 0x400 doubles the size used by AMD64 systems and maintains
the size used by EM64T.
BUG=b:118420852
TEST=S3 on Grunt and verify 0x2f000-0x30000 uncorrupted
Change-Id: Ib1d590ee4afb06ca649afd6ad253cdfd969ae777
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/29277
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Richard Spiegel <richard.spiegel@silverbackltd.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>