brcm47xx: use kernel 3.8.10 as default kernel

The biggest change with this kernel is a new partition parser.

SVN-Revision: 36480

target/linux/brcm47xx/Makefile

@@ -11,7 +11,7 @@ BOARD:=brcm47xx
 BOARDNAME:=Broadcom BCM947xx/953xx
 FEATURES:=squashfs usb pcmcia
 
-LINUX_VERSION:=3.6.11
+LINUX_VERSION:=3.8.10
 
 include $(INCLUDE_DIR)/target.mk
 DEFAULT_PACKAGES += wpad-mini kmod-switch kmod-diag nvram