soc/intel/cannonlake: Add support for EMMC DLL update

Add option to have customized DLL setting for EMMC interface to make
EMMC able to run at HS400 speed.

BUG=None

Change-Id: I38bc022d8c05dd1fbd03dc26aa6f33cd249e8248
Signed-off-by: Lijian Zhao <lijian.zhao@intel.com>
Reviewed-on: https://review.coreboot.org/23600
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/cannonlake/chip.h

@@ -155,7 +155,12 @@ struct soc_intel_cannonlake_config {
 	/* eMMC and SD */
 	uint8_t ScsEmmcEnabled;
 	uint8_t ScsEmmcHs400Enabled;
-	uint8_t PchScsEmmcHs400TuningRequired;
+	/* Need to update DLL setting to get Emmc running at HS400 speed */
+	uint8_t EmmcHs400DllNeed;
+	/* 0-39: number of active delay for RX strobe, unit is 125 psec */
+	uint8_t EmmcHs400RxStrobeDll1;
+	/* 0-78: number of active delay for TX data, unit is 125 psec */
+	uint8_t EmmcHs400TxDataDll;
 	uint8_t ScsSdCardEnabled;
 	uint8_t ScsUfsEnabled;