Clean up header to reuse __riscv definition

Change-Id: I3f7026b982f8503fd814be6feb99725f8e60b274
Signed-off-by: Rebecca Chang Swee Fun <rebecca.chang@starfivetech.com>
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/54005
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
1 file changed