MIPS: ralink: adds support for RT2880 SoC family

Add support code for rt2880 SOC.

The code detects the SoC and registers the clk / pinmux settings.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/5176/
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 27a4bfa..c1997db 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1144,7 +1144,7 @@
 
 config MIPS_L1_CACHE_SHIFT
 	int
-	default "4" if MACH_DECSTATION || MIKROTIK_RB532 || PMC_MSP4200_EVAL
+	default "4" if MACH_DECSTATION || MIKROTIK_RB532 || PMC_MSP4200_EVAL || SOC_RT288X
 	default "6" if MIPS_CPU_SCACHE
 	default "7" if SGI_IP22 || SGI_IP27 || SGI_IP28 || SNI_RM || CPU_CAVIUM_OCTEON
 	default "5"