Enable Acoustic noise mitigation for blipper and set slew rate to 1/8
which is calibrated value for the board.
BUG=b:187760191
BRANCH=dedede
TEST=build firmware to UPD and Acoustic noise test
Change-Id: I187702c23712416eaaaaf1e210dcfc6b2c560041
Signed-off-by: Zanxi Chen <chenzanxi@huaqin.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55610
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
50c099fe15