i2c: efm32: new bus driver

This was tested on a EFM32GG-DK3750 devboard that has a temperature
sensor and an eeprom on its i2c bus.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 5e914ef..80998d73 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -433,6 +433,13 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-designware-pci.
 
+config I2C_EFM32
+	tristate "EFM32 I2C controller"
+	depends on ARCH_EFM32 || COMPILE_TEST
+	help
+	  This driver supports the i2c block found in Energy Micro's EFM32
+	  SoCs.
+
 config I2C_EG20T
 	tristate "Intel EG20T PCH/LAPIS Semicon IOH(ML7213/ML7223/ML7831) I2C"
 	depends on PCI