regmap: select CONFIG_REGMAP while REGMAP_SCCB is set

regmap: select CONFIG_REGMAP while REGMAP_SCCB is set

REGMAP_SCCB is selected by ov772x and ov9650 drivers,
but CONFIG_REGMAP may not, so building will fails:

rivers/media/i2c/ov772x.c: In function ov772x_probe:
drivers/media/i2c/ov772x.c:1360:22: error: variable ov772x_regmap_config has initializer but incomplete type
  static const struct regmap_config ov772x_regmap_config = {
                      ^~~~~~~~~~~~~
drivers/media/i2c/ov772x.c:1361:4: error: const struct regmap_config has no member named reg_bits

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 696d63bc4c77 ("media: ov772x: use SCCB regmap")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190704093553.49904-1-yuehaibing@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>