g: use GLOBALSEC_REGION5 for flash log access control
g: use GLOBALSEC_REGION5 for flash log access control

Flash log space access needs to be explicitly enabled. The previously
chosen for this purpose global security region 7 is also used by the
TPM endorsement procedure, and this may cause race condition resulting
in flash log space not accessible.

Let's use previously unused region 5 instead. This is how the regions
are configured after this patch on a system where RO_A and RW_B are
active (bit 0 enables region in general, bit 1 enables reads, bit 2
enables writes):

Reg    Base       Size     Enable bits
 0   00040000    000027ff      3        # RO_A
 1   00084000    00037fff      3        # RW_B
 2   00044000    000387ff      7        # RW_A
 3   0007c800    000037ff      7        # NVMEM
 4   000bc800    000037ff      7        # NVMEM
 5   00083800    000007ff      3        # Flash log
 6   00028400    0000000f      3        # Info 1 board ID
 7   00028000    000007ff      3        # Info 1 endorsement seed

BRANCH=cr50. cr50-mp
BUG=b:132287488
TEST=verified that there is no flash log lockups when the device boots
     with an unendorsed TPM.

Change-Id: I4fc65989b3930d91ed8e076310ecb58bac5f085e
Signed-off-by: Vadim Bendebury <5515d6d2d0829cbe0dd0dcf2094aaded06d58514@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1656158
Reviewed-by: Andrey Pronin <53bbebe6910b11f7aa2d1daaa466658eb4cba5f2@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec