soc/intel_adsp: Unbreak xcc builds

Recent linker changes got ahead of the toolchain and started using
features not available in the binutils 2.23-based Xtensa toolchain.
Specifically:

+ The section arguments to objcopy don't accept wildcards.

+ It's not legal to have an ALLOC section emitted to a region outside
  a declared MEMORY space.  So various non-mapped sections populated
  by C structs have to be put somewhere with an explicit address.

+ The older linker won't automatically create an empty section just
  because you assigned to ".", so the Zephyr tests that lack a
  .fw_metadata section get rejected by rimage.  The fix here is a
  little clumsy: copy the section out of zephyr.elf into a
  (potentially-zero-length) temporary file, then add it back to
  main.mod as a final step.

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