The driver currently reads a mediatek,eint-detect-mode property from DT,
which determines certain register configurations. Since there are no
users of the property, it doesn't directly describe the hardware, and
the default value (4) is known to work across multiple boards, remove
the handling for this property and always assume mode 4 is used. The
property can be properly introduced in the binding in the future if
different boards actually need different configurations.
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>