[MIPS] Add support for BCM47XX CPUs.

Note that the BCM4710 does not support the wait instruction, this
is not a mistake in the code.
    
It originally comes from the OpenWrt patches.
    
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Felix Fietkau <nbd@openwrt.org>
Cc: Florian Schirmer <jolt@tuxbox.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/proc.c

@@ -82,6 +82,8 @@ static const char *cpu_name[] = {
 	[CPU_VR4181]	= "NEC VR4181",
 	[CPU_VR4181A]	= "NEC VR4181A",
 	[CPU_SR71000]	= "Sandcraft SR71000",
+	[CPU_BCM3302]	= "Broadcom BCM3302",
+	[CPU_BCM4710]	= "Broadcom BCM4710",
 	[CPU_PR4450]	= "Philips PR4450",
 	[CPU_LOONGSON2]	= "ICT Loongson-2",
 };