spi: Kconfig: Add FSL_ESPI entry

Added FSL_ESPI entry on Kconfig with help description.

Signed-off-by: Jagan Teki <jteki@openedev.com>
Cc: Haikun Wang <haikun.wang@freescale.com>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 9c6c5d5..2c0046d 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -80,6 +80,13 @@
 
 endif # if DM_SPI
 
+config FSL_ESPI
+	bool "Freescale eSPI driver"
+	help
+	  Enable the Freescale eSPI driver. This driver can be used to
+	  access the SPI interface and SPI NOR flash on platforms embedding
+	  this Freescale eSPI IP core.
+
 config TI_QSPI
 	bool "TI QSPI driver"
 	help