riscv: Extend cpufeature.c to detect vendor extensions

Instead of grouping all vendor extensions into the same riscv_isa_ext
that standard instructions use, create a struct
"riscv_isa_vendor_ext_data_list" that allows each vendor to maintain
their vendor extensions independently of the standard extensions.
xandespmu is currently the only vendor extension so that is the only
extension that is affected by this change.

An additional benefit of this is that the extensions of each vendor can
be conditionally enabled. A config RISCV_ISA_VENDOR_EXT_ANDES has been
added to allow for that.

Signed-off-by: Charlie Jenkins <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Reviewed-by: Andy Chiu <[email protected]>
Tested-by: Yu Chien Peter Lin <[email protected]>
Reviewed-by: Yu Chien Peter Lin <[email protected]>
Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-1-0af7587bbec0@rivosinc.com
Signed-off-by: Palmer Dabbelt <[email protected]>

0 files changed, 0 insertions, 0 deletions