soc/intel/skylake: Enable Systemagent IMGU

Camera and Imaging device should be enabled for camera usecase,
FSP provides a UPD to enable/disable the SA IMGU (Imaging Unit)
expose the same as a config option in devicetree.cb

Also remove a redundant assignment for PchCio2Enable.

BUG=None
BRANCH=None
TEST=lspci should list 00:05:00

Change-Id: I4cf7daf41bfaf4dcba414921cac2e7e12bf89f37
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-on: https://review.coreboot.org/18365
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/intel/skylake/chip.h

@@ -205,6 +205,7 @@ struct soc_intel_skylake_config {
 
 	/* Camera */
 	u8 Cio2Enable;
+	u8 SaImguEnable;
 
 	/* eMMC and SD */
 	u8 ScsEmmcEnabled;