dt-bindings: pinctrl: at91-pio4: add microchip,sama7g5

Add compatible string for microchip sama7g5 SoC.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200917131257.273882-1-eugen.hristev@microchip.com


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