PH1-LD11 and PH1-LD20 have much pin controlling in common, so I
added a single driver shared between them in the initial commit.
However, the Ethernet pin-mux settings I am going to add are
different with each other, and they may diverge more as the
progress of development. Split it into two dedicated drivers.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>