reboot/mdm9x15: Adding fastboot reboot with pm8921

Using pm8921 driver on 9x15 with pm8018 since pm8018 is
a subset of pm8921 and can be reused for rebooting.

Change-Id: I556653bab13685da69fead8c67f011a9809fb3d0
diff --git a/target/mdm9615/rules.mk b/target/mdm9615/rules.mk
index facbbd6..6ab270b 100644
--- a/target/mdm9615/rules.mk
+++ b/target/mdm9615/rules.mk
@@ -14,6 +14,8 @@
 
 MODULES += \
 	dev/keys \
+	dev/ssbi \
+	dev/pmic/pm8921 \
 	lib/ptable
 
 DEFINES += \