Switch AOSP X86/MIPS compiler to gcc4.8

Change-Id: Ifeee2c7d696c8a8e96e52c6ca51434260bdae5f8
diff --git a/core/combo/TARGET_linux-x86.mk b/core/combo/TARGET_linux-x86.mk
index bfbf51e..2669595 100755
--- a/core/combo/TARGET_linux-x86.mk
+++ b/core/combo/TARGET_linux-x86.mk
@@ -23,7 +23,7 @@
 endif
 
 ifeq ($(strip $(TARGET_GCC_VERSION_EXP)),)
-TARGET_GCC_VERSION := 4.7
+TARGET_GCC_VERSION := 4.8
 else
 TARGET_GCC_VERSION := $(TARGET_GCC_VERSION_EXP)
 endif