Input: ps2-gpio - refactor struct ps2_gpio_data

Refactor struct ps2_gpio_data in order to clearly separate RX and TX
state data.

This change intends to increase code readability and does not bring any
functional change.

Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215160208.34826-2-danilokrummrich@dk-develop.de


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>