MIPS: MSP71xx: remove inline marking of EXPORT_SYMBOL functions

EXPORT_SYMBOL and inline directives are contradictory to each other.
The patch fixes this inconsistency.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Denis Efremov <yefremov.denis@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: trivial@kernel.org
Cc: ldv-project@linuxtesting.org
Patchwork: https://patchwork.linux-mips.org/patch/5227/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>