Revert "Make detection of DSA interface more robust"

This reverts commit 0ee973b2b2.

Turns out that this workaround simply reduced the size of the window
where this issue can occur.

The previous change now ensures that the DSA tree is always fully
setup by the time nameif runs.

board/common/rootfs/usr/libexec/infix/init.d/20-nameif

@@ -14,24 +14,6 @@ for file in /sys/firmware/qemu_fw_cfg/by_name/opt/mactab/raw /etc/mactab; do
 	fi
 done
 
-# Sometimes the sysfs is not populated when the switch driver is loaded, with the result
-# that the DSA interface was not found (no /dsa/tagging entry in sysfs. See issue #685.
-#
-# This mitigates that problem by waiting for sysfs to come up if a DSA switch is found
-if [ -n "$(devlink -j dev info | jq -r '.info.[].driver' | grep -q mv88e6085)" ]; then
-	timeout=50
-	while [ -z "$(ls /sys/class/net/*/dsa/tagging)" ]; do
-		timeout=$((timeout-1))
-		if [ $timeout -eq 0 ]; then
-			logger -k -p user.emerg -t "$ident" "Failed to find DSA interface"
-			exit 1
-		fi
-		sleep 0.1
-	done
-
-	logger -k -p user.notice -t "$ident" "Found DSA interface in $timeout seconds"
-fi
-
 # Find CPU interfaces used for connecting to a switch managed by DSA
 for netif in /sys/class/net/*; do
 	iface=$(basename "$netif")