soc/intel/skylake: Remove CCA object for IMGU and CIO2 devices

IMGU and CIO2 devices do support the hardware managed cache
coherency and hence removing the CCA object which was
reporting that cache coherency is not supported.

BUG=none
BRANCH=none
TEST=Build and boot soraka. Dump ACPI tables and verify that
CCA object is not present.

Change-Id: I14b0a92eafe193e9004d2dad0957a3fe8d05d313
Signed-off-by: V Sowmya <v.sowmya@intel.com>
Reviewed-on: https://review.coreboot.org/21678
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sumeet R Pawnikar <sumeet.r.pawnikar@intel.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/skylake/acpi/ipu.asl

@@ -18,7 +18,6 @@ Device (IMGU)
 {
 	Name (_ADR, 0x00050000)
 	Name (_DDN, "Imaging Unit")
-	Name (_CCA, ZERO)
 	Name (CAMD, 0x01)
 }
 
@@ -27,6 +26,5 @@ Device (CIO2)
 {
 	Name (_ADR, 0x00140003)
 	Name (_DDN, "Camera and Imaging Subsystem")
-	Name (_CCA, ZERO)
 	Name (CAMD, 0x00)
 }