drivers: gpio: esp32: check pin number range

As a complement of 7689abee,
which fixed an issue where gpio number could errouneously be
set to a number greater than 32 in DTS, there is also another
situation where driver instance can be configured with a pin number
greater than 32.
This PR adds another check in GPIO driver to confirm
whether the PIN number is within valid bounds.

Signed-off-by: Sylvio Alves <sylvio.alves@espressif.com>