mfd: twl4030: TWL4030_CORE needs REGMAP and REGMAP_I2C

Selecting REGMAP_I2C defaults REGMAP to "y", no need to explicitly select it.

This fixes:

- Because of REGMAP, a bunch of:
drivers/mfd/twl-core.c:221:29:
error: array type has incomplete element type
drivers/mfd/twl-core.c:224:3:
error: field name not in record or union initializer
drivers/mfd/twl-core.c:224:3:
error: (near initialization for 'twl4030_regmap_config')

- Because of REGMAP_I2C:
drivers/mfd/twl-core.c: In function 'twl_probe':
drivers/mfd/twl-core.c:1256:3: error: implicit declaration of function 'devm_regmap_init_i2c' [-Werror=implicit-function-declaration]

---
 drivers/mfd/Kconfig |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

index 1c0abd4..47ad4e2 100644
@@ -292,6 +292,7 @@ config TWL4030_CORE
 	bool "Texas Instruments TWL4030/TWL5030/TWL6030/TPS659x0 Support"
 	depends on I2C=y && GENERIC_HARDIRQS
 	select IRQ_DOMAIN
+	select REGMAP_I2C
 	help
 	  Say yes here if you have TWL4030 / TWL6030 family chip on your board.
 	  This core driver provides register access and IRQ handling

1.7.4.4