ARM: dts: am335x-evmsk: adjust mmc2 param to allow suspend

mmc2 used for wl12xx was missing the keep-power-in suspend
parameter. As a result the board couldn't reach suspend state.
Signed-off-by: NEyal Reizer <eyalr@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am335x-evmsk.dts

@@ -672,6 +672,7 @@
 	ti,non-removable;
 	bus-width = <4>;
 	cap-power-off-card;
+	keep-power-in-suspend;
 	pinctrl-names = "default";
 	pinctrl-0 = <&mmc2_pins>;