pinctrl: armada-37xx: Add missing GPIO-only pins

gpio1_5 and gpio2_2 are GPIO-only pins. Add them into MPP groups table
so they are properly exported as valid pin numbers.

Fixes: 87466ccd ("pinctrl: armada-37xx: Add pin controller support for Armada 37xx")
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220805122202.23174-1-pali@kernel.org


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>