phy-core: phy_get: Leave error logging to the caller

In various cases errors may be expected, ie probe-deferral or a call to
phy_get from a driver where the use of a phy is optional.

Rather then adding all sort of complicated checks for this, and/or adding
special functions like devm_phy_get_optional, simply don't log an error,
and let deciding if get_phy returning an error really should result in a
dev_err up to the caller.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>