MIPS: Spelling s/confugrations/configurations/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7573/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>