fleex: set PD on unused interrupt
fleex: set PD on unused interrupt

If the SKU does not populate the base accel, then we should not
enable the interrupt and add a pull down to keep the line from floating.

BRANCH=none
BUG=none
TEST=verfied similar change on bobba

Change-Id: I85fdfc001bcafdf4d56a2459837c2f4f4f0b64fa
Signed-off-by: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1336288
Reviewed-by: Furquan Shaikh <6be5c96c464778f89679b1062a2e0a6af93d2aa5@chromium.org>
Reviewed-by: Karthikeyan Ramasubramanian <5f7313966b13e2a933e6857bda169ba157fc04ea@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec