ps8xxx: Increase FW init delay to 50ms
ps8xxx: Increase FW init delay to 50ms

The latest app note indicates the ps8815 firmware may take up to 50ms to
be ready.

BRANCH=none
BUG=b:186189039
TEST=buildall passes

Change-Id: Ibc5ee2e6030d19b91d6c0b8a493aa05dd31c77e4
Signed-off-by: Caveh Jalali <08e24a66aefda7a55ca7d73f8903e0fb16eec763@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3087983
Reviewed-by: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>
Commit-Queue: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>

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