amlogic: Rework Makefiles

Now that every piece is in place, the makefiles can be refactored and
slightly beautified removing useless and redundant parts.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Change-Id: If74e1909df52d475cf4b0dfed819d07d3a4c85b9
2 files changed