npcx: Clear IRQ11B bit when PM 1 is in enhanced mode
npcx: Clear IRQ11B bit when PM 1 is in enhanced mode

The bit IRQ11B of register HIIRQC is meaningful only when PM Channel 1
is in PC87570-Compatible. In previous commit, we deprecate use of
PC87570 mode but set the bit unintentionally. This will not cause any
bug but may make confused when reading the code.

Modified sources:
1. lpc.c: CLear IRQ11B in register HIIRQC.

BUG=chrome-os-partner:34346
TEST=make buildall -j; verify on Wheatley
BRANCH=none
Signed-off-by: CHLin <CHLIN56@nuvoton.com>

Change-Id: I594222c29557add847a1f689859fdf558d64fdd3
Reviewed-on: https://chromium-review.googlesource.com/358536
Commit-Ready: CH Lin <49997681dc186e71092740314bf6c6feeca6e227@nuvoton.com>
Tested-by: CH Lin <49997681dc186e71092740314bf6c6feeca6e227@nuvoton.com>
Reviewed-by: Mulin Chao <6bbc5af053a1dfdc363be6857f30de4ac3bcbd16@nuvoton.com>
Reviewed-by: Amit Maoz <09d1f7cdc99a7cab99232c678550cde1f85738e1@nuvoton.com>
Reviewed-by: Shawn N <5259333ce42e3ace6a73988cec7115ed9d3a661a@chromium.org>

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