msm: rpm: Add sysfs nodes to read driver and fw versions

Add RPM platform driver to export RPM kernel driver and firmware
version using

	cat /sys/devices/platform/msm_rpm/driver_version
	cat /sys/devices/platform/msm_rpm/fw_version

Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>
diff --git a/arch/arm/mach-msm/board-msm8x60.c b/arch/arm/mach-msm/board-msm8x60.c
index ea28f98c..5393b9f 100644
--- a/arch/arm/mach-msm/board-msm8x60.c
+++ b/arch/arm/mach-msm/board-msm8x60.c
@@ -4699,6 +4699,11 @@
 
 #endif /* CONFIG_MSM_SDIO_AL */
 
+static struct platform_device msm_rpm_device = {
+	.name = "msm_rpm",
+	.id = -1,
+};
+
 static struct platform_device *charm_devices[] __initdata = {
 	&msm_charm_modem,
 #ifdef CONFIG_MSM_SDIO_AL
@@ -4893,6 +4898,7 @@
 #endif
 
 	&msm_tsens_device,
+	&msm_rpm_device,
 
 };