ARM: make arrays containing machine compatible strings const

The definition

	static const char *axxia_dt_match[] __initconst = {
		...

defines a changable array of constant strings. That is you must not do:

	*axxia_dt_match[0] = 'k';

but

	axxia_dt_match[0] = "different string";

is fine. So the annotation __initconst is wrong and yields a compiler
error when other really const variables are added with __initconst.

As the struct machine_desc member dt_compat is declared as

	const char *const *dt_compat;

making the arrays const is the better alternative over changing all
annotations to __initdata.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-shmobile/setup-emev2.c

@@ -37,7 +37,7 @@ static void __init emev2_map_io(void)
 	iotable_init(emev2_io_desc, ARRAY_SIZE(emev2_io_desc));
 }
 
-static const char *emev2_boards_compat_dt[] __initconst = {
+static const char *const emev2_boards_compat_dt[] __initconst = {
 	"renesas,emev2",
 	NULL,
 };