regulator: mcp16502: Select REGMAP_I2C to fix build error

Fix build error when CONFIG_REGMAP_I2C=m && CONFIG_REGULATOR_MCP16502=y.

drivers/regulator/mcp16502.o: In function `mcp16502_probe':
mcp16502.c:(.text+0xca): undefined reference to `__devm_regmap_init_i2c'
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/Kconfig

@@ -570,6 +570,7 @@ config REGULATOR_MC13892
 config REGULATOR_MCP16502
 	tristate "Microchip MCP16502 PMIC"
 	depends on I2C && OF
+	select REGMAP_I2C
 	help
 	  Say y here to support the MCP16502 PMIC. This driver supports
 	  basic operations (get/set voltage, get/set operating mode)