refactor(arm_fpga): move command line code into separate function

The code dealing with finding the command line and inserting that into
the DTB is somewhat large, and drowns the other DT handlers in our
fpga_prepare_dtb() function.

Move that code into a separate function, to improve readability.

Change-Id: I828203c4bb248d38a2562fcb6afdefedf3179f8d
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
1 file changed