soc/intel/cannonlake: Remove SmbusEnable

Remove the SmbusEnable config option from devicetree and instead
use the state of the PCI device to determine if it should be
enabled or disabled.

Change-Id: Id362009e4c8e91699d1ca9bb3c2614e21cfc462a
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/29552
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/cannonlake/chip.h

@@ -166,9 +166,6 @@ struct soc_intel_cannonlake_config {
 	 * clksrc. */
 	uint8_t PcieClkSrcClkReq[CONFIG_MAX_ROOT_PORTS];
 
-	/* SMBus */
-	uint8_t SmbusEnable;
-
 	/* eMMC and SD */
 	uint8_t ScsEmmcHs400Enabled;
 	/* Need to update DLL setting to get Emmc running at HS400 speed */