arch: riscv: custom: add Andes CSR support
Rework Andes-specific CSR to use RISC-V custom CSR common code.
Move these stuff to 'arch/riscv/custom/andes':
1. Rename 'soc_v5.h' to 'andes_csr.h' for CSR definitions.
2. Replace '_start' with '__reset' hook for low-level CSR initialization.
3. Move CSR context to common macro '__custom_csr_save/restore_context'.
4. Move 'EXECIT' CSR support to common code.
5. Move PMA CSR driver to common code.
6. Use RISC-V common linker.ld instead of SoC-specific linker.ld.
Signed-off-by: Jimmy Zheng <jimmyzhe@andestech.com>
28 files changed