bcm28xx: update kernel

target/config/Config.in.kernelversion

@@ -228,7 +228,7 @@ config ADK_TARGET_KERNEL_GIT
 	depends on ADK_TARGET_KERNEL_VERSION_GIT
 	default "6064a9bdf48cefbccc4f6472dd04251f0dec1931" if ADK_TARGET_ARCH_CSKY
 	default "6a2f2e4198eaff63ee75f6085ce9f966c47b4441" if ADK_TARGET_ARCH_LM32
-	default "cfa29b46af94d83e31aa000dbaee553f9c4d670c" if ADK_TARGET_BOARD_BCM28XX
+	default "31a8651c138253007c66e1be176cdc839b416842" if ADK_TARGET_BOARD_BCM28XX
 	default "f8d3b2a0fa5054aaed0f14cd457db9d8922bb167" if ADK_TARGET_SYSTEM_ADSP_BF537
 	default "e7c8afc1dda7b7c18596d90ad6a17ae886650b72" if ADK_TARGET_SYSTEM_KINETIS_K70
 	default "902739f3353150ac9eb69ad995098f3079d862a3" if ADK_TARGET_SYSTEM_SOLIDRUN_CLEARFOG
@@ -240,7 +240,7 @@ config ADK_TARGET_KERNEL_GIT_VER
 	string "kernel version"
 	depends on ADK_TARGET_KERNEL_VERSION_GIT
 	default "4.9.56" if ADK_TARGET_ARCH_CSKY
-	default "4.9.37" if ADK_TARGET_BOARD_BCM28XX
+	default "4.9.70" if ADK_TARGET_BOARD_BCM28XX
 	default "4.4.37" if ADK_TARGET_SYSTEM_BEAGLEBONE_BLACK
 	default "4.4.52" if ADK_TARGET_SYSTEM_PHYTEC_WEGA
 	default "2.6.33" if ADK_TARGET_SYSTEM_KINETIS_K70