xtensa-build-zephyr.py: checksum newly generated rimage_config.toml file

[marc-hb]

Add new file generated since commit cf9a444 ("toml: modularise TOML configuration")

Optional because it's not generated for all platforms.

[marc-hb]

New checksum visible in https://sof-ci.01.org/sofpr/PR8921/build3224/build and https://github.com/thesofproject/sof/actions/runs/8195163022/job/22412800176?pr=8921 when applicable.

build-sof-staging  
|-- sof  
|   +-- intel  
|       +-- sof-ipc4  
|           |-- arl  
|           |   +-- community  
|           |       +-- sof-arl.ri  -> ../../mtl/community/sof-mtl.ri 
|           |-- arl-s  
|           |   +-- community  
|           |       +-- sof-arl-s.ri  -> ../../mtl/community/sof-mtl.ri 
|           |-- mtl  
|           |   +-- community  
|           |       +-- sof-mtl.ri  	sha256=6b4faff7d4ee2fce2022b97a05db034f331a1dee1db75b8c37671cadea7ca7d6
|           |-- sof-arl-s.ldc  -> sof-mtl.ldc 
|           |-- sof-arl.ldc  -> sof-mtl.ldc 
|           +-- sof-mtl.ldc  	sha256=73130542b6e1d4a6a37a1366bca7c378adcd9942c9801b4ce7c5a87d60b3cf96
|-- sof-info  
|   +-- mtl  
|       |-- boot.mod.gz  	sha256=a4c7a2571cb913356df877b3b9a7129fe796c3d12e153b8d3e2207b3c83f21df
|       |-- config.gz  
|       |-- generated_configs.c.gz  	sha256=aae122088fde61cf48885197f7ce703cc764ba46194da5fc9fa7e36b4e727928
|       |-- generated_rimage_config.toml  	sha256=e1999cf4b746c4567ac62569315f321e53a6f2d72bcfb02a21b81aef6dbd1a96
|       |-- main.mod.gz  
|       |-- sof_versions.h  	sha256=03bd5c7c3d8f997e71cc922234407ba526bcbb79a6af8ab1da466c069db5f039
|       |-- stripped-main.elf.gz  	sha256=1b58e367c6c3ffdf626027a128517eff519687efc272885fc26f5b1ed69e563e
|       |-- stripped-zephyr.elf.gz  	sha256=081d0936b8785dd6b9790993ac0d2f6b90ec75d70c7a18e57d3f72839efb30f1
|       |-- westconfig.ini  
|       |-- zephyr.elf.gz  

[marc-hb]

Unrelated suspend/failure in https://sof-ci.01.org/sofpr/PR8921/build3225/devicetest/index.html

1 device unavailable in https://sof-ci.01.org/sofpr/PR8921/build3226/devicetest/index.html

Everything else green including https://sof-ci.01.org/sof-pr-viewer/#/build/PR8921/build13691064