RISC-V: add auipc elements to parse_asm header

Instruction parsing should not be done in individual code, but instead
supported by central

Right now kgdb and kprobes parse instructions and at least kprobes (and
the upcoming auipc+jalr alternative fixer-function) need the auipc
instruction.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-6-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>