Allow extended usage of internal flash

[BrianPugh]

This is a naive way of shoving some more data into the internal flash if the user specifies EXTENDED=1

[kbeckmann]

I see what you're trying to do, and also why, but doing like this will be hard to maintain.

I would much prefer having one single .ld file and then based on a build flag:

• Use 128 or 256k internal flash size
• Place the logo etc on either extflash or internal flash

This could also be solved with includes from the .ld file, not sure what is the most clean solution.

[nopjne]

What if we simply increase it to 256 without the make parameter addition. As long as people have the patched ocd everything works.