Added new eswp custom instruction into ASM and mem file. WARNING: Do not try to compile the .S with eswp in the file because it is not a real riscv instruction. Was added into the .S to match the .mem so students could see visually how it looks like. -Raphael R.

Lab2 functional

Modified typos in code comments

Modified addr divided by 4 in riscv_core_tb

Updated 'riscv_pkg.vhd' to take into account the extra material given to students.