Drop DRAMT write as it's only rewriting the power on default.
PMCR write is required. Update comment on its purpose and move to
end of sdram_enable().
Change-Id: I62e8b2531f0f297ffb7db440db89ffa65771b7d5
Signed-off-by: Keith Hui <buurin@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38383
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>