Input: mpr121 - drop redundant wakeup handling

The driver currently calls device_init_wakeup() and manually toggles
IRQ wake in suspend and resume paths. This is unnecessary since the
I2C core already handles wakeup configuration when the device is
described in Device Tree with the "wakeup-source" property.

Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Link: https://patch.msgid.link/20260309071413.92709-1-phucduc.bui@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>