i2c: lpi2c: add lpi2c driver for i.MX7ULP

Add lpi2c driver for i.MX7ULP.
Need to enable the two options to use this driver:
CONFIG_DM_I2C=y
CONFIG_SYS_I2C_IMX_LPI2C=y

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Heiko Schocher <hs@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 39f62da..8ac7aaf 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -109,6 +109,12 @@
 	  the I2C API meaning that any I2C operations will immediately fail
 	  for now.
 
+config SYS_I2C_IMX_LPI2C
+	bool "NXP i.MX LPI2C driver"
+	depends on ARCH_MX7ULP
+	help
+	  Add support for the NXP i.MX LPI2C driver.
+
 config SYS_I2C_MXC
 	bool "NXP i.MX I2C driver"
 	depends on MX6