gpio: wcd934x: Fix shift-out-of-bounds error

In the Linux kernel, the following vulnerability has been resolved: gpio: wcd934x: Fix shift-out-of-bounds error bit-mask for pins 0 to 4 is BIT(0) to BIT(4) however we ended up with BIT(n - 1) which is not right, and this was caught by below usban check UBSAN: shift-out-of-bounds in drivers/gpio/gpio-wcd934x.c:34:14