pckbd: implement i8042_mmio_init() function

This enables use to set the required value of extended_state directly during
device init rather than in i8042_mm_init().

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20220624134109.881989-27-mark.cave-ayland@ilande.co.uk>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
1 file changed