as: unrecognized option '-EL' while compiling android kernel on ubuntu 14

ARCH=arm64
SUBARCH=arm64
CROSS_COMPILE=aarch64-linux-android-

Following is the output of make

# make
CHK     include/generated/uapi/linux/version.h
CHK     include/generated/utsrelease.h
CALL    scripts/checksyscalls.sh
CC      scripts/mod/empty.o
as: unrecognized option '-EL'
make[2]: *** [scripts/mod/empty.o] Error 1
make[1]: *** [scripts/mod] Error 2    
make: *** [scripts] Error 2

still the "as" is used from binutils (/usr/bin/as) instead of /usr/bin/aarch64-linux-android-as despite of gcc versions, gcc-4.4 gcc-4.6 gcc-4.8, ubuntu always install same binutils

renaming /usr/bin/as does not help & make fails

how can I make "make" use right "as" while cross compile.