ARC: dts: Replace deprecated snps,nr-gpios property for snps,dw-apb-gpio-port devices

snps,dw-apb-gpio-port is deprecated since commit ef42a8da
("dt-bindings: gpio: dwapb: Add ngpios property support"). The
respective driver supports this since commit 7569486d ("gpio: dwapb:
Add ngpios DT-property support") which is included in Linux v5.10-rc1.

This change was created using

	git grep -l snps,nr-gpios arch/arc/boot/dts | xargs perl -p -i -e 's/\bsnps,nr-gpios\b/ngpios/

.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>