Some of the platforms use platform specific CSR access functions for
configuring implementation specific CSRs (such as PMA registers).
Extend the common csr_read_num() and csr_write_num() to allow custom
CSRs so that platform specific CSR access functions are not needed.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20250930153216.89853-1-apatel@ventanamicro.com
Signed-off-by: Anup Patel <anup@brainfault.org>