mvebu: remove non-existant board name solidrun,clearfog-a1

In 02_network, the board name solidrun,clearfog-a1 is used in a
case, but it does not seem to be used/exist anywhere else in OpenWrt.

The valid strings are:
- solidrun,clearfog-pro-a1
- solidrun,clearfog-base-a1

Fixes: 12795ec9f1 ("mvebu: split interface configuration for
clearfog pro and base")

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/mvebu/cortexa9/base-files/etc/board.d/02_network

@@ -30,7 +30,6 @@ mvebu_setup_interfaces()
 	marvell,axp-gp)
 		ucidef_set_interface_lan "eth0 eth1 eth2 eth3"
 		;;
-	solidrun,clearfog-a1|\
 	solidrun,clearfog-pro-a1)
 		# eth0 is standalone ethernet
 		# eth1 is switch