mmc: support hs400 enhanced strobe mode

eMMC 5.1+ supports HS400 Enhances Strobe mode without the need for
tuning procedure.
The flow is as following:
 - set HS_TIMIMG (Highspeed)
 - Host change freq to <= 52Mhz
 - set the bus width to Enhanced strobe and DDR8Bit(CMD6),
   EXT_CSD[183] = 0x86 instead of 0x80
 - set HS_TIMING to 0x3 (HS400)
 - Host change freq to <= 200Mhz
 - Host select HS400 enhanced strobe complete

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index a4a6a6c..890ef35 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -135,6 +135,18 @@
 	  cards. The IO voltage must be switchable from 3.3v to 1.8v. The bus
 	  frequency can go up to 208MHz (SDR104)
 
+config MMC_HS400_ES_SUPPORT
+	bool "enable HS400 Enhanced Strobe support"
+	help
+	  The HS400 Enhanced Strobe mode is support by some eMMC. The bus
+	  frequency is up to 200MHz. This mode does not tune the IO.
+
+config SPL_MMC_HS400_ES_SUPPORT
+	bool "enable HS400 Enhanced Strobe support in SPL"
+	help
+	  The HS400 Enhanced Strobe mode is support by some eMMC. The bus
+	  frequency is up to 200MHz. This mode does not tune the IO.
+
 config MMC_HS400_SUPPORT
 	bool "enable HS400 support"
 	select MMC_HS200_SUPPORT