net: phy: smsc: reintroduced unconditional soft reset

We detected some problems using the smsc lan8720a in combination with
i.MX28 and tracked this down to commit 21009686 ("net: phy: smsc: move
smsc_phy_config_init reset part in a soft_reset function")
With 21009686 the generic soft reset is replaced by a specific function
which handles power down state correctly. But additionally the soft reset
itself got conditional and is therefore also only performed if the phy is
in power down state.

This patch keeps the conditional wake up from power down, but
re-introduces the unconditional soft reset using the generic soft reset
function.
It was tested on linux-4.1.25 and linux-4.7.0-rc2.

Signed-off-by: Manfred Schlaegl <manfred.schlaegl@ginzinger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>