Update documentation of instruction extensions for CV32E40P version 2.
Created by: jeremybennett
These changes particularly relate to how tool chain support is
invoked using -march. We take the opportunity to remove caveats
about ISA extensions not supported in the tool chain, since all
are now supported in both GCC and Clang/LLVM.
* docs/source/instruction_set_extensions.rst: Add -march tool chain invocations for each ISA extension and remove all caveats about compiler support.
Signed-off-by: Jeremy Bennett jeremy.bennett@embecosm.com