Change AWK command for memory to be more simple

[chimps-ahoy]

This just get's the 'Mem' token from the input of AWK, which I feel is simpler and makes more sense (we don't get a duplication of Mem in the header file).

I could see it being argued to leave the explicit 'Mem' within the "Icon" field, because it shows as an example how that field works for people configuring for the first time