Add build.config

Bug: 19661035
Change-Id: Ia84f480a95d3da2efaf28d7357eb630f7a1190ae

build.config

+ARCH=arm
+BRANCH=android-msm-shamu-3.10
+CROSS_COMPILE=arm-eabi-
+DEFCONFIG=shamu_defconfig
+EXTRA_CMDS=''
+KERNEL_DIR=private/msm-moto
+LINUX_GCC_CROSS_COMPILE_PREBUILTS_BIN=prebuilts/gcc/linux-x86/arm/arm-eabi-4.8/bin
+FILES="
+arch/arm/boot/zImage-dtb
+vmlinux
+System.map
+"