Input: ps2-gpio - enforce GPIOs flag open drain

Input: ps2-gpio - enforce GPIOs flag open drain

The PS/2 bus defines the data and clock line be open drain, therefore
for both enforce the particular GPIO flags in the driver.

Without enforcing to flag at least the clock gpio as open drain we run
into the following warning:

WARNING: CPU: 1 PID: 40 at drivers/gpio/gpiolib.c:3175 gpiochip_enable_irq+0x54/0x90

gpiochip_enable_irq() warns on a GPIO being configured as output while
serving as IRQ source without being flagged as open drain.

Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215180829.63543-4-danilokrummrich@dk-develop.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>