Add method for converting DDR4 speed in MHz to MT/s. Checks that MHz is
within a speed grade range.
BUG=b:167155849
TEST=ddr4-test unit test
BRANCH=Zork
Change-Id: I1433f028afb794fe3e397b03f5bd0565494c8130
Signed-off-by: Rob Barnes <robbarnes@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45343
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Rob Barnes