spi: spi-mtk-nor: Fix checkpatch spacing error

Fix checkpatch error:

  ERROR: space required before the open parenthesis '('
  #295: FILE: spi-mtk-nor.c:295:
  +		switch(op->data.dir) {

Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1616566602-13894-6-git-send-email-f.fangjian@huawei.com


Signed-off-by: Mark Brown <broonie@kernel.org>