ARM: 8846/1: warn if divided syntax assembler is used

Remove the -mno-warn-deprecated assembler flag to make sure the GNU
assembler warns in case non-unified syntax is used.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>