mips: Update the email address of Geert Uytterhoeven

All my Sony addresses are defunct.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6817/


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