ARM: mach-shmobile: Use DT_MACHINE for armadillo 800 eva

Use DT_MACHINE_START() on the r8a7740 based armadillo 800 eva 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 7828a7a..ed770b9 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -97,6 +97,7 @@
 	bool "Armadillo-800 EVA board"
 	depends on ARCH_R8A7740
 	select ARCH_REQUIRE_GPIOLIB
+	select USE_OF
 
 config MACH_MARZEN
 	bool "MARZEN board"