arm64: dts: imx8mq-librem5: Set cap-power-off-card for usdhc2

This is needed for brcmfmac to turn the card off in suspend
since 8c31706.

Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Author: dos1

arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi

@@ -1437,6 +1437,7 @@
 	max-frequency = <50000000>;
 	disable-wp;
 	cap-sdio-irq;
+	cap-power-off-card;
 	keep-power-in-suspend;
 	wakeup-source;
 	status = "okay";