soc: intel_adsp: tools: fix ace20 fw load flow

Use the correct register to read ROM status on intel_adsp_ace20.

Without this this fix, firmware load is successful but
boot takes extra 2 seconds and following warning was emitted:

WARNING:cavs-fw:Load failed?  ROM_STATUS = 0x0

The log-only mode (-l) was not working at all and is fixed
by this commit.

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>