ARM: mach-shmobile: Use DT_MACHINE for KZM9G

Use DT_MACHINE_START() on the sh73a0 based KZM9G board.

Also include a tiny DTS file to describe the board and
update the Kconfig dependencies to select CONFIG_USE_OF.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig
index c39413a..2ed3995 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -102,6 +102,7 @@
 	bool "KZM-A9-GT board"
 	depends on ARCH_SH73A0
 	select ARCH_REQUIRE_GPIOLIB
+	select USE_OF
 
 comment "SH-Mobile System Configuration"