aboot: add compile time option to select hdmi primary

Enable DISPLAY_HDMI_PRIMARY macro to make hdmi as default primary
panel.

Change-Id: I4c5d09b5355e3f6ed6bd408a5c47e71799a381b1
diff --git a/app/aboot/aboot.c b/app/aboot/aboot.c
index 74e17e0..e84e2e5 100644
--- a/app/aboot/aboot.c
+++ b/app/aboot/aboot.c
@@ -117,6 +117,8 @@
 #define EXPAND(NAME) #NAME
 #define TARGET(NAME) EXPAND(NAME)
 
+#define DISPLAY_PANEL_HDMI "hdmi"
+
 #ifdef MEMBASE
 #define EMMC_BOOT_IMG_HEADER_ADDR (0xFF000+(MEMBASE))
 #else
@@ -3786,6 +3788,11 @@
 	if (!check_alarm_boot()) {
 #endif
 		dprintf(SPEW, "Display Init: Start\n");
+#if DISPLAY_HDMI_PRIMARY
+	if (!strlen(device.display_panel))
+		strlcpy(device.display_panel, DISPLAY_PANEL_HDMI,
+			sizeof(device.display_panel));
+#endif
 #if ENABLE_WBC
 		/* Wait if the display shutdown is in progress */
 		while(pm_app_display_shutdown_in_prgs());