arm64: dts: marvell: armada-37xx: declare PCIe reset pin

commit a5470af981a0cc14a650af8da5186668971a4fc8 upstream.

One pin can be muxed as PCIe endpoint card reset.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>