target: init: Add runtime check is SSD feature enabled

Add runtime check function for SSD_ENABLE feature defined to
avoid ifdef-ery and improve readability of the code.

Change-Id: I239e00f30ff70b87eddfd7e09bd674cd01614587
diff --git a/include/target.h b/include/target.h
index b70306d..dc86864 100644
--- a/include/target.h
+++ b/include/target.h
@@ -47,6 +47,7 @@
 void target_serialno(unsigned char *buf);
 void target_fastboot_init(void);
 void target_load_ssd_keystore(void);
+bool target_is_ssd_enabled(void);
 struct mmc_device *target_mmc_device();
 
 
diff --git a/target/init.c b/target/init.c
index 3b2f432..a2c1d93 100644
--- a/target/init.c
+++ b/target/init.c
@@ -107,6 +107,15 @@
 #endif
 }
 
+__WEAK bool target_is_ssd_enabled(void)
+{
+#ifdef SSD_ENABLE
+	return 1;
+#else
+	return 0;
+#endif
+}
+
 __WEAK void target_load_ssd_keystore(void)
 {
 }