Re-use Core control Agent

Created by: AyoubJalali

The following PR related to re-use of the existent core control agent. Things to Know : The CVA6 has only the boot_addr as an input of the signals in the core control agent, so the other signals have no effect. The fetch_toogle_seq as @MikeOpenHWGroup mention was added to verify a requirement of the embedded cores. We can change the boot_addr value from the uvme_cva6_cfg.sv file, or add a simulation option +boot_addr = (some value), with that you should give the same value to spike (add a cva6.py option : --isspostrun_opts=some value ) and the linker to guaranty that your test run very well, you should know also that there is some limitation in the boot_addr values (raise a INSTR_ACCESS_FAULT exception).