Remove unused drivers and some fast calibration implementations to align with the latest MTK memory reference code. Signed-off-by: Ryan Chuang <ryan.chuang@mediatek.corp-partner.google.com> Change-Id: I3b235cbceb231898f00fce7905f596eab54ca595 Reviewed-on: https://review.coreboot.org/c/coreboot/+/57275 Reviewed-by: Yu-Ping Wu <yupingso@google.com> Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.corp-partner.google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>