mfd: Remove redundant AB8500_I2C_CORE Kconfig entry

During ab8500-core clean-up the Kconfig entry for AB8500_I2C_CORE
was left remnant. This patch simply removes it.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

drivers/mfd/Kconfig

@@ -716,16 +716,6 @@ config AB8500_CORE
 	  the irq_chip parts for handling the Mixed Signal chip events.
 	  This chip embeds various other multimedia funtionalities as well.
 
-config AB8500_I2C_CORE
-	bool "AB8500 register access via PRCMU I2C"
-	depends on AB8500_CORE && MFD_DB8500_PRCMU
-	default y
-	help
-	  This enables register access to the AB8500 chip via PRCMU I2C.
-	  The AB8500 chip can be accessed via SPI or I2C. On DB8500 hardware
-	  the I2C bus is connected to the Power Reset
-	  and Mangagement Unit, PRCMU.
-
 config AB8500_DEBUG
        bool "Enable debug info via debugfs"
        depends on AB8500_CORE && DEBUG_FS