Allow passing extra CFLAGS by CFLAGS environment varable
Allow passing extra CFLAGS by CFLAGS environment varable

jsr-d10/android_bootable_bootloader_lk,jsr-d10/android_bootable_bootloader_lk,jsr-d10/android_bootable_bootloader_lk,jsr-d10/android_bootable_bootloader_lk,jsr-d10/android_bootable_bootloader_lk