arm: omap3: beagle: Ensure msecure is mux'd to be able to set the RTC

Without msecure beeing high it isn't possible to set (or start)
the RTC.

Tested with a BeagleBoard C4.

Signed-off-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/board-omap3beagle.c b/arch/arm/mach-omap2/board-omap3beagle.c
index be71426..d64ed97 100644
--- a/arch/arm/mach-omap2/board-omap3beagle.c
+++ b/arch/arm/mach-omap2/board-omap3beagle.c
@@ -579,6 +579,9 @@
 	omap_nand_flash_init(NAND_BUSWIDTH_16, omap3beagle_nand_partitions,
 			     ARRAY_SIZE(omap3beagle_nand_partitions));
 
+	/* Ensure msecure is mux'd to be able to set the RTC. */
+	omap_mux_init_signal("sys_drm_msecure", OMAP_PIN_OFF_OUTPUT_HIGH);
+
 	/* Ensure SDRC pins are mux'd for self-refresh */
 	omap_mux_init_signal("sdrc_cke0", OMAP_PIN_OUTPUT);
 	omap_mux_init_signal("sdrc_cke1", OMAP_PIN_OUTPUT);