ARM: qemu-arm: enable RTC

QEMU provides an emulated ARM AMBA PrimeCell PL031 RTC.

The patch sets the base address in the board include file according to the
definition in hw/arm/virt.c of the QEMU source. It defines the Kconfig
option for the existing driver, and enables the RTC driver in
qemu_arm64_defconfig and qemu_arm_defconfig as well as the date command.

We need an RTC to provide the GetTime() runtime service in the UEFI
subsystem.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Tested-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index a3f8c8a..5436509 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -48,6 +48,13 @@
 	help
 	  Support for Epson RX8010SJ Real Time Clock devices.
 
+config RTC_PL031
+	bool "Enable ARM AMBA PL031 RTC driver"
+	help
+	  The ARM PrimeCell Real Time Clock (PL031) is an optional SoC
+	  peripheral based on the Advanced Microcontroller Bus Architecture
+	  (AMBA). It is emulated in QEMU virtual ARM machines.
+
 config RTC_MV
 	bool "Enable Marvell RTC driver"
 	depends on DM_RTC