ARM: 8221/1: PJ4: allow building in Thumb-2 mode

Two files that get included when building the multi_v7_defconfig target
fail to build when selecting THUMB2_KERNEL for this configuration.

In both cases, we can just build the file as ARM code, as none of its
symbols are exported to modules, so there are no interworking concerns.
In the iwmmxt.S case, add ENDPROC() declarations so the symbols are
annotated as functions, resulting in the linker to emit the appropriate
mode switches.

Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
(cherry picked from commit 13d1b957)
Cc: <stable@vger.kernel.org> # v3.18+
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>