MIPS: BCM63xx: Fix typo in cpu-feature-overrides file.

Fix typo: CONFIG_BCMCPU_IS_63xx does not exist;
CONFIG_BCM63XX_CPU_63xx is the valid config option.
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
To: linux-mips@linux-mips.org
Cc: Maxime Bizon <mbizon@freebox.fr>
Patchwork: http://patchwork.linux-mips.org/patch/901/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-bcm63xx/cpu-feature-overrides.h

@@ -24,7 +24,7 @@
 #define cpu_has_smartmips		0
 #define cpu_has_vtag_icache		0
 
-#if !defined(BCMCPU_RUNTIME_DETECT) && (defined(CONFIG_BCMCPU_IS_6348) || defined(CONFIG_CPU_IS_6338) || defined(CONFIG_CPU_IS_BCM6345))
+#if !defined(BCMCPU_RUNTIME_DETECT) && (defined(CONFIG_BCM63XX_CPU_6348) || defined(CONFIG_BCM63XX_CPU_6345) || defined(CONFIG_BCM63XX_CPU_6338))
 #define cpu_has_dc_aliases		0
 #endif