Will give you a generic reason why you got that error and then delve into the specific error that you got.
You get the "Command not found" error when you try to execute a command which does not exist on your system or exists in a directory which is not in your shell's search path.
When you execute:
$ which ls
the shell starts searching in the ":" separated paths in $PATH environment variable to see if a file by the name "ls" exists. The search stops upon the first find. If it doesn't find the file in any of the paths, it gives the "Command not found" error.
make: /opt/edlk/usr/bin/arm-linux-gcc: Command not found
says that your make file contained a target entry which was supposed to be compiled by "/opt/edlk/usr/bin/arm-linux-gcc". Most probably it would be defined in a $CC variable at the top of the makefile.
But which is your make file? As per the man page here
it says that by default make looks into GNUmakefile, makefile, and Makefile, in that order.
So see which makefile you are using first.
Once you've got that figured out, find the entry "/opt/edlk/usr/bin/arm-linux-gcc" in it. That's the command that your shell is executing but it isn't there.
Normally most makefiles use the system's GCC compiler instead of using their own. If I were you at this stage, I'd do the following:
1. Check if arm-linux-gcc is installed on my system or not (check by running the "which" command as described above)
2. If its not there, install it and go to step 1. If it is there, go to step 3.
3. Create a symlink from "/opt/edlk/usr/bin/arm-linux-gcc" to <insert absolute path of arm-linux-gcc here>
4. Run your make again
How to do step 3? - # ln -s <abs path of arm-linux-gcc> "/opt/edlk/usr/bin/arm-linux-gcc"
Hope this helps.