a5: Remove ethernet overlay

Change-Id: Ied161bf8badf60e437f43c8d2a47c485b662233c
a5: Reduce system partition size
* a5ul and a5chl have smaller system sizes than a5dug and a5dwg

Change-Id: Ia049a6858cdea88cecb19c210fc06a78d98a2ece
a5: Use own camera blobs