[MIPS] DEC: Fix modpost warning.

  LD      vmlinux
  SYSMAP  System.map
  SYSMAP  .tmp_System.map
  MODPOST vmlinux
WARNING: drivers/built-in.o(.data+0x2480): Section mismatch: reference to .init.text: (between 'sercons' and 'ds_parms')

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