According to GCC documentation -m(no-)thumb-interwork is
meaningless in AAPCS configurations. Also clang does not
support the flag:
  clang-5.0: error: unknown argument: '-mno-thumb-interwork'

Just drop -mno-thumb-interwork in AEABI configuration.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>