Added architecture detection

[Aidan-McNay]

Previously, we encountered errors where the targett architecture needed to change based on the version of the RISCV GCC we were using. The new setup should use environment.mk to detect the version and update flags appropriately. This also updated all of the Makefiles to use the compiler and version specified in environment.mk, eliminating the need to change compiler paths for each Makefile if the users had the toolchain installed in a different location.

@jeffdi @RTimothyEdwards would love any feedback/comments, hopefully this fixes the issue