spi: bcm2835aux: Fix build error without CONFIG_DEBUG_FS

When building CONFIG_DEBUG_FS is not set
gcc warn this:

drivers/spi/spi-bcm2835aux.c: In function bcm2835aux_spi_probe:
drivers/spi/spi-bcm2835aux.c:591:2: error: too many arguments to function bcm2835aux_debugfs_create
  bcm2835aux_debugfs_create(bs, dev_name(&pdev->dev));
  ^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/spi/spi-bcm2835aux.c:145:13: note: declared here
 static void bcm2835aux_debugfs_create(struct bcm2835aux_spi *bs)

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 8048d151

 ("spi: bcm2835aux: add driver stats to debugfs")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>