{mb, security}: Use EC_REBOOT_FLAG_IMMEDIATE for cold reboots

The value 0 passed as the reboot_flags argument to
google_chromeec_reboot is now explicitly defined as
EC_REBOOT_FLAG_IMMEDIATE in ec_commands.h.

Update calls to google_chromeec_reboot with EC_REBOOT_COLD to use the
new flag for clarity and to ensure the intended EC-based reboot is
performed.

This change doesn't introduce anything new, so there's no change
in behavior.

Change-Id: I6701c94101c5085cfcc7fbf2e614c4f23d843225
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/90278
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>

src/mainboard/google/bluey/reset.c

@@ -8,5 +8,5 @@
 void do_board_reset(void)
 {
 	if (CONFIG(EC_GOOGLE_CHROMEEC))
-		google_chromeec_reboot(EC_REBOOT_COLD, 0);
+		google_chromeec_reboot(EC_REBOOT_COLD, EC_REBOOT_FLAG_IMMEDIATE);
 }

src/mainboard/google/herobrine/reset.c

@@ -7,5 +7,5 @@
    but this works well enough for our purposes. */
 void do_board_reset(void)
 {
-	google_chromeec_reboot(EC_REBOOT_COLD, 0);
+	google_chromeec_reboot(EC_REBOOT_COLD, EC_REBOOT_FLAG_IMMEDIATE);
 }

src/mainboard/google/trogdor/reset.c

@@ -7,5 +7,5 @@
    but this works well enough for our purposes. */
 void do_board_reset(void)
 {
-	google_chromeec_reboot(EC_REBOOT_COLD, 0);
+	google_chromeec_reboot(EC_REBOOT_COLD, EC_REBOOT_FLAG_IMMEDIATE);
 }

src/security/vboot/ec_sync.c

@@ -56,7 +56,7 @@ void vboot_sync_ec(void)
 
 	case VB2_REQUEST_REBOOT_EC_TO_RO:
 		printk(BIOS_INFO, "EC Reboot requested. Doing cold reboot\n");
-		if (google_chromeec_reboot(EC_REBOOT_COLD, 0))
+		if (google_chromeec_reboot(EC_REBOOT_COLD, EC_REBOOT_FLAG_IMMEDIATE))
 			printk(BIOS_EMERG, "Failed to get EC to cold reboot\n");
 
 		halt();