Adds a new user-configurable string to arch/Config.in.riscv, and in
arch/arch.mk.riscv appends it to GCC_TARGET_ARCH.
This enables custom extensions/combinations to be easily configured.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Jesse Taube <Mr.Bossman075@gmail.com>
[Arnout:
- fix check-package warnings
- introduce ARCH_RISV_ISA_EXTRA to simplify stripping of quotes
]
Signed-off-by: Arnout Vandecappelle <arnout@rnout.be>