psp_verstage: report developer mode to PSP

Add platform_report_mode function which report current developer mode
status to the PSP. L1 widevine app in the PSP will use this information
to select key box.

BUG=b:211058864
TEST=build and boot guybrush
TEST=build picasso chrome os boards

Signed-off-by: Kangheui Won <khwon@chromium.org>
Change-Id: I04b5fcfa338b485b36f1b946203f32823385c0b1
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61369
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jason Glenesk <jason.glenesk@gmail.com>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
diff --git a/src/soc/amd/common/psp_verstage/psp_verstage.c b/src/soc/amd/common/psp_verstage/psp_verstage.c
index 05c14d6..9f34700 100644
--- a/src/soc/amd/common/psp_verstage/psp_verstage.c
+++ b/src/soc/amd/common/psp_verstage/psp_verstage.c
@@ -314,6 +314,8 @@
 	if (retval)
 		reboot_into_recovery(ctx, retval);
 
+	platform_report_mode(vboot_developer_mode_enabled());
+
 	post_code(POSTCODE_UPDATE_BOOT_REGION);
 
 	/*