zephyr: it8xxx2: pinmux: read pinctrl-0 property instead of hardcoding
zephyr: it8xxx2: pinmux: read pinctrl-0 property instead of hardcoding

The parameters in pinmux_pin_set() are read by pinctrl-0 property
instead of hardcoding.

Since the i2c alternate function will be set to GPIO input in
shim:gpio.c if gpio.dts has a corresponding set. So it must
be set back to i2c alternate.

BUG=b:210800948
BRANCH=none
TEST=zmake configure -b zephyr/projects/it8xxx2_evb/

Signed-off-by: Tim Lin <38846f7070d5770410e9ef8b439c72e7b53a72c5@ite.corp-partner.google.com>
Change-Id: I079f4091ef7627d252a435107ef39b0363265faf
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3346769
Reviewed-by: Denis Brockus <6b21e8190fb5e373363fb95271367073a16474ef@chromium.org>
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