msm7x27a: usb: Add usb enumeration support.

For eMMC targets, sending product serial number from CID of
MMC as serial number for USB enumeration to kernel as well as
for fastboot.

For NAND targets, using target name as serial number.

Change-Id: I2704b80f670ae6b415cf220b87534ce94b93848b
diff --git a/target/msm7627a/init.c b/target/msm7627a/init.c
index a591f46..86ceef7 100644
--- a/target/msm7627a/init.c
+++ b/target/msm7627a/init.c
@@ -288,3 +288,13 @@
 void target_battery_charging_enable(unsigned enable, unsigned disconnect)
 {
 }
+
+#if _EMMC_BOOT
+void target_serialno(unsigned char *buf)
+{
+	unsigned int serialno;
+	serialno =  mmc_get_psn();
+	sprintf(buf,"%x",serialno);
+}
+#endif
+