Revert "soc: intel_adsp: fix linker script for XCC"

This reverts commit ee7773fb.

Unfortunately this mechanism doesn't seem to actually work on the SDK
linker.  The emitted sections, when passed a symbol name as the "start
address" just appear wherever the "." variable was pointing (in this
case, into the cached region).  That breaks the kernel coherence
layer, obviously.

Revert for now, which will regress the XCC build fix pending a proper
root cause.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>