aboot: mdtp: perform verification depending on MDTP efuse

This commit add  support for reading the MDTP eFuse (or emulated
eFuse located in the MDTP partition) and performing DIP and firmware
verification only if the MDTP is enabled in the eFuse.

Change-Id: Iff04b3d18f9baba026ebf61cbeead37fa585a7bd
diff --git a/app/aboot/mdtp.h b/app/aboot/mdtp.h
index 68914f4..9975899 100644
--- a/app/aboot/mdtp.h
+++ b/app/aboot/mdtp.h
@@ -107,6 +107,9 @@
 /* Start Firmware Lock verification process */
 int mdtp_fwlock_verify_lock();
 
+/* Return whether the MDTP is currently enabled or disabled in HW */
+int mdtp_fuse_get_enabled(bool *enabled);
+
 /* Display the "Firmware Valid" screen */
 void show_OK_msg();