- Moved code for SSB to RACH mapping config to new function
- Moved RA preambles configuration routine to new function
- Removed irrelevant arguments to nr_get_prach_resources
- turned some struct members and local vars into global vars
- added checks on the RA Type as per TS 38.321 clause 5.1.1
- minor cleanups
- currently only 4-step RA is available