Updated all references relevant to the assembler compiler toolchain.

Created by: pietraferreira

cores/cv32e40p/user_manual/source:

* corev_hw_loop.rst: Renamed, updated references to the assembler compiler toolchains and general corrections.
* index.rst: Updated references to the assembler compiler toolchains and general corrections.
* instruction_set_extensions.rst: Likewise.
* integration.rst: Likewise.
* intro.rst: Likewise.
* perf_counters.rst: Likewise.
* pipeline.rst: Likewise.
* sleep.rst: Likewise.

cores/cv32e40p/user_manual/origin:

* user_manual.rst: Updated document revision table accordingly.

Signed-off-by: Pietra F T Madio pietra.ferreira@embecosm.com