ITE: soc: pull-down GPIO L/K groups and set GPIOH7 output low at default

GPIO L/K groups:
On IT81202 (128-pins package), the pins of GPIO group K and L aren't
bonding with pad. So we configure these pins as internal pull-down
at default to prevent leakage current due to floating.

GPIOH7:
On IT81202/IT81302, the GPIOH7 isn't bonding with pad and is left
floating internally. We need to enable internal pull-down for the pin
to prevent leakage current, but IT81202/IT81302 doesn't have the
capability to pull it down. We can only set it as output low,
so we enable output low for it at initialization to prevent leakage.

After setting: power saving=2.26mA

Signed-off-by: Tim Lin <tim2.lin@ite.corp-partner.google.com>