clearfog: linux: enable SFP

The DTS files on longer have GPIO hogs which enable operation of the SFP
module. Therefore we have to enable the SFP PHY so that the link can
come up.

Change-Id: I6570466a5fba48d092636dcf4c6c32e4a1ae823a
diff --git a/board/czechlight/clearfog/linux.fragment b/board/czechlight/clearfog/linux.fragment
index 43a563b..434c640 100644
--- a/board/czechlight/clearfog/linux.fragment
+++ b/board/czechlight/clearfog/linux.fragment
@@ -23,3 +23,5 @@
 
 # For the Lumentum OCM
 CONFIG_SPI_SPIDEV=y
+
+CONFIG_SFP=y