Input: st1232 - add IDLE state as ready condition

Input: st1232 - add IDLE state as ready condition

The st1232 can switch from NORMAL to IDLE state after the configured
idle time (by default 8 s). If the st1232 is not reset during probe, it
might already be ready but in IDLE state. Since it does not enter NORMAL
state in this case, probe fails.

Fix the wait function to report the IDLE state as ready, too.

Fixes: f605be6a57b4 ("Input: st1232 - wait until device is ready before reading resolution")
Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Link: https://lore.kernel.org/r/20210219110556.1858969-1-m.tretter@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>