Enable PD communication in RO for external display

This patch makes EC enable PD communication if it's running in
manual recovery mode. This is required to show recovery screen
on a type-c monitor.

This patch also makes EC-EFS ignore power availability. It will
make EC verify & jump to RW even if power is sourced by a barrel
jack adapter. This should allow depthcharge to show screens
(e.g. broken, warning) on a type-c monitor.

BUG=b:72387533
BRANCH=none
TEST=On Fizz with type-c monitor, verify
- Recovery screen is displayed in manual recovery mode.
- Critical update screen is displayed in normal mode.
- Warning screen is displayed in developer mode.
Monitors tested: Dingdong, Dell S2718D

Change-Id: Ib53e02d1e5c0f5b2d96d9a02fd33022f92e52b04
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/898346
Reviewed-by: Randall Spangler <rspangler@chromium.org>

common/main.c

@@ -27,6 +27,7 @@
 #include "timer.h"
 #include "uart.h"
 #include "util.h"
+#include "vboot.h"
 #include "watchdog.h"
 
 /* Console output macros */
@@ -168,8 +169,15 @@ test_mockable __keep int main(void)
 	button_init();
 #endif /* defined(CONFIG_DEDICATED_RECOVERY_BUTTON | CONFIG_VOLUME_BUTTONS) */
 
-#if !defined(CONFIG_VBOOT_EFS) && \
-	defined(CONFIG_RWSIG) && !defined(HAS_TASK_RWSIG)
+#if defined(CONFIG_VBOOT_EFS)
+	/*
+	 * For RO, it behaves as follows:
+	 *   In recovery, it enables PD communication and returns.
+	 *   In normal boot, it verifies and jumps to RW.
+	 * For RW, it returns immediately.
+	 */
+	vboot_main();
+#elif defined(CONFIG_RWSIG) && !defined(HAS_TASK_RWSIG)
 	/*
 	 * Check the RW firmware signature and jump to it if it is good.
 	 *