arm: socfpga: Fix ethernet reset handling

arm: socfpga: Fix ethernet reset handling

The following patch caused cpu_eth_init() to not be called anymore
for DM-capable boards:

commit c32a6fd07b1839e4a45729587ebc8e1c55601a4d
Date:   Sun Jan 17 14:51:56 2016 -0700
    net: Don't call board/cpu_eth_init() with driver model

This breaks ethernet on SoCFPGA, since we use that function to un-reset
the ethernet blocks. Invoke the ethernet reset function from arch_misc_init()
instead to fix the breakage.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Chin Liang See <clsee@altera.com>
Cc: Denis Bakhvalov <denis.bakhvalov@nokia.com>