Revert "mb/intel/shadowmountain: Add the ASL code"

Revert "mb/intel/shadowmountain: Add the ASL code"

This reverts commit 2151f7561d728a9280d69d20ef56a9fe44db7cb1.

Reason for revert: It depends on the shadowmountain ramstage patch.

Error on the builder:

    IASL       /cb-build/coreboot.0/default/INTEL_SHADOWMOUNTAIN/dsdt.aml
src/mainboard/intel/shadowmountain/dsdt.asl:4:10: fatal error: baseboard/ec.h: No such file or directory
 #include <baseboard/ec.h>
          ^~~~~~~~~~~~~~~~
compilation terminated.

Change-Id: I9fa5e8cc2ad485bf82bfbda151bc46d26faef7ab
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50055
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Christian Walter <christian.walter@9elements.com>
Reviewed-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>