media: max2175: Fix build error without CONFIG_REGMAP_I2C

If CONFIG_REGMAP_I2C is not set, building fails:

drivers/media/i2c/max2175.o: In function `max2175_probe':
max2175.c:(.text+0x1404): undefined reference to `__devm_regmap_init_i2c'

Select REGMAP_I2C to fix this.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: b47b79d8 ("[media] media: i2c: max2175: Add MAX2175 support")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>