[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>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index a8bdc08..6648f9b 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -44,6 +44,20 @@
 	  note that a kernel built with this option selected will not be
 	  able to run on normal units.
 
+config BCM47XX
+	bool "BCM47XX based boards"
+	select DMA_NONCOHERENT
+	select HW_HAS_PCI
+	select IRQ_CPU
+	select SYS_HAS_CPU_MIPS32_R1
+	select SYS_SUPPORTS_32BIT_KERNEL
+	select SYS_SUPPORTS_LITTLE_ENDIAN
+	select SSB
+	select SSB_DRIVER_MIPS
+	select GENERIC_GPIO
+	help
+	 Support for BCM47XX based boards
+
 config MIPS_COBALT
 	bool "Cobalt Server"
 	select DMA_NONCOHERENT