Draft: Add DV's riscv-test-platform (bmDV)

• New environment environments/bmDV.sh
• New platform platforms/bmDV/ (riscv-test-platform as a submodule)
• Adaptation of all codes that supported by environment bmVEC to also support bmDV
• Adaptation of bmVECto play nice with bmDV (function names and headers)

To use the new platform:

source environments/bmDV.sh ENV=<p-m,v-msu> NHARTS=1 PK=0
cd codes/<kernel>/
make

MR left in Draft because not all environments of bmDV are usable (virtual won't work with current CSR reading (stream, for example)).

For now, both environments coexist.

cc: @pvizcai1 @fbanchel