rambi: configure SD card signals

Rambi 1.5 boards use the native SD card controller on baytrail.
Therefore, enable those signals. The CLK, D*, and CMD pins use
2K pulls as these were shown to not exhibit any errors when
doing reads or writes to a DDR50 sd card.

Note that if a servo is connected on needs to enable the
sd_vref_sel rail to pp1800 as this causes issues with card
detect if it is not set to pp1800.

BUG=chrome-os-partner:24312
BRANCH=None
TEST=Built and booted. Tested sd card read and write works in kernel.
     Also noted that write protect detection works as well.

Change-Id: I520e2808acbd8494534fcb710411dbc0e12fc874
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/178961
Reviewed-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: http://review.coreboot.org/4990
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins)
1 file changed