Input: add support for GRLIB APBPS2 PS/2 Keyboard/Mouse

APBPS2 is a PS/2 core part of GRLIB found in SPARC32/LEON
products.

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>