ARM i.MX51: return gracefully on different socs

Code called from an initcall can be maybe called for
machines it's not intended for. So check for valid
machines and return gracefully if an incompatible machine
is found.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-mx5/cpu.c

@@ -79,6 +79,9 @@ EXPORT_SYMBOL(mx51_revision);
  */
 static int __init mx51_neon_fixup(void)
 {
+	if (!cpu_is_mx51())
+		return 0;
+
 	if (mx51_revision() < MX51_CHIP_REV_3_0 && (elf_hwcap & HWCAP_NEON)) {
 		elf_hwcap &= ~HWCAP_NEON;
 		pr_info("Turning off NEON support, detected broken NEON implementation\n");