arm: Use common .lds file where possible

arm: Use common .lds file where possible

Each cpu directory currently has its own .lds file. This is only needed
in most cases because the start.o file is in a different subdir.

Now that we can factor out this difference, we can move most cpus over
to the common .lds file.

Signed-off-by: Simon Glass <sjg@chromium.org>