ramips: move ESW reset to preinit on RT305x/RT5350

RT305x/RT5350 SoCs require the switch to be reset before touching the ethernet
interface, otherwise the driver will panic.
As we already init the ethernet in preinit we therefor need to reset the switch
before that.

Signed-off-by: Felix Kaechele <felix@fetzig.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@37027 3c298f89-4303-0410-b956-a3cf2f4a3e73