ARM: imx: deconstruct mxc_rnga initialization

The rnga platform device is initialized for all imx31 machines
from its own initcall, but is never initialized anywhere else.

This moves the platform device creation into both the imx31
dt and non-dt machine init sequences, which has basically the
exact same effect as before, but makes it more obvious what
is going on, while reducing the amount of code and removing
the last user of cpu_is_mx31().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/mach-imx/imx31-dt.c

@@ -28,10 +28,22 @@ static void __init imx31_dt_timer_init(void)
 	mx31_clocks_init_dt();
 }
 
+/* FIXME: replace with DT binding */
+static const struct resource imx31_rnga_res[] __initconst = {
+	DEFINE_RES_MEM(MX31_RNGA_BASE_ADDR, SZ_16K),
+};
+
+static void __init imx31_dt_mach_init(void)
+{
+	platform_device_register_simple("mxc_rnga", -1, imx31_rnga_res,
+					ARRAY_SIZE(imx31_rnga_res));
+}
+
 DT_MACHINE_START(IMX31_DT, "Freescale i.MX31 (Device Tree Support)")
 	.map_io		= mx31_map_io,
 	.init_early	= imx31_init_early,
 	.init_irq	= mx31_init_irq,
 	.init_time	= imx31_dt_timer_init,
+	.init_machine	= imx31_dt_mach_init,
 	.dt_compat	= imx31_dt_board_compat,
 MACHINE_END