firmware: cs_dsp: Add mock DSP memory map for KUnit testing

firmware: cs_dsp: Add mock DSP memory map for KUnit testing

Add helper functions to implement an emulation of the DSP memory map.

There are three main groups of functionality:

1. Define a mock cs_dsp_region table.
2. Calculate the addresses of memory and algorithms from the firmware
   header in XM.
3. Build a mock XM header in emulated XM.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20241212143725.1381013-3-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>