MIPS: AR7: prevent race between clock initialization and devices registration

ar7_regiser_devices needs ar7_clocks_init to have been called first,
however clock.o is currently linked later due to its order in the Makefile,
therefore ar7_clocks_init always gets called later than ar7_register_devices
because both have the same initcall level. Fix this by moving
ar7_register_devices to the right initcall level.
Reported-by: Michael J. Evans <mjevans1983@gmail.com>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/1212/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/ar7/platform.c

@@ -647,4 +647,4 @@ static int __init ar7_register_devices(void)
 
 	return 0;
 }
-arch_initcall(ar7_register_devices);
+device_initcall(ar7_register_devices);