MIPS: TXX9: use IS_ENABLED() macro

commit b33b44073734842ec0c75d376c40d0471d6113ff upstream.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3334/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --cc arch/mips/txx9/generic/setup.c
Simple merge

diff --cc arch/mips/txx9/generic/setup_tx4939.c
Simple merge

diff --cc arch/mips/txx9/rbtx4939/setup.c
Simple merge