This adds support for the Intel Falcon SoC for GPON.
Support for the Falcon SoC was removed in commit c821836395 svn rev:
40392 from OpenWrt, this commit adds it again.
This patch adds a new subtarget for the Falcon SoC, but it still misses
all the drivers needed to control the GPON part.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>