platform: msm_shared: Add backlight control function

Add backlight control function to msm power on/power
off sequences. This decouples the backlight power
on from the panel power on, removing the flicker
that would occur during a panel reinititialization.

Change-Id: I37df5d44d6b18529a0204f743a0fcb79d477d96d
diff --git a/platform/msm_shared/include/msm_panel.h b/platform/msm_shared/include/msm_panel.h
index 9e4a8b9..b586de0 100755
--- a/platform/msm_shared/include/msm_panel.h
+++ b/platform/msm_shared/include/msm_panel.h
@@ -215,6 +215,7 @@
 	/* function entry chain */
 	int (*power_func) (int enable);
 	int (*clk_func) (int enable);
+	int (*bl_func) (int enable);
 	int (*pll_clk_func) (int enable, struct msm_panel_info *);
 };