drivers: gpio: esp32: fix pin number value

ESP32 has 2 GPIOs: gpio0 and gpio1.
Zephyr DTS model requires pin definition in dts file
from 0 to 31, meaning that when some pin within gpio1 range
is required, gpio driver needs to increament this value
by 32, required by LL API.

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