amd/stoneyridge: Make cbmem_top SMM aware

Make the default for SMM_TSEG_SIZE depend on SMM_TSEG in addition to
HAVE_SMI_HANDLER.

Change the value returned by cbmem_top() to carve out a range to be
used by TSEG.  The SMM Mask register has a granularity of 128KB but
align the value to 16MB to keep down the number of variable MTRRs
required.

Change-Id: I54ffc10108862b7d022fbbd92bf97525b349df27
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/21491
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed