rtc: Add drivers/rtc/rtc-mrst.c

Provide the standard kernel rtc driver interface on top of the vrtc layer
added in the previous patch.

Signed-off-by: Feng Tang <feng.tang@intel.com>
LKML-Reference: <20101110172911.3311.20593.stgit@localhost.localdomain>
[Fixed swapped arguments on IPC]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
[Cleaned up and the device creation moved to arch/x86/platform]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2883428..4941cad 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -463,6 +463,18 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-cmos.
 
+config RTC_DRV_VRTC
+	tristate "Virtual RTC for Moorestown platforms"
+	depends on X86_MRST
+	default y if X86_MRST
+
+	help
+	Say "yes" here to get direct support for the real time clock
+	found on Moorestown platforms. The VRTC is a emulated RTC that
+	derives its clock source from a real RTC in the PMIC. The MC146818
+	style programming interface is mostly conserved, but any
+	updates are done via IPC calls to the system controller FW.
+
 config RTC_DRV_DS1216
 	tristate "Dallas DS1216"
 	depends on SNI_RM