gpio: aspeed: Remove the name for bank array

The bank array name is only used to determine if the GPIO offset is valid,
and this condition can be replaced by checking if the offset exceeds the
ngpio property.

Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Link: https://lore.kernel.org/r/20241008081450.1490955-5-billy_tsai@aspeedtech.com


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>