omap3: String-based reboot mode handling

This switches reboot mode handling to a string-based interface, that allows more
flexibility to set a common interface with the next generations of OMAP devices.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/board/lge/sniper/sniper.c b/board/lge/sniper/sniper.c
index f093f97..b2c8e97 100644
--- a/board/lge/sniper/sniper.c
+++ b/board/lge/sniper/sniper.c
@@ -109,7 +109,7 @@
 
 	/* Reboot mode */
 
-	reboot_mode[0] = omap_reboot_mode();
+	omap_reboot_mode(reboot_mode, sizeof(reboot_mode));
 
 	if (keys[0])
 		reboot_mode[0] = 'r';
@@ -159,12 +159,12 @@
 
 void reset_misc(void)
 {
-	omap_reboot_mode_store('u');
+	omap_reboot_mode_store("u");
 }
 
 int fb_set_reboot_flag(void)
 {
-	return omap_reboot_mode_store('b');
+	return omap_reboot_mode_store("b");
 }
 
 #ifndef CONFIG_SPL_BUILD