net: phy: aquantia: wait for FW reset before checking the vendor ID

Checking the firmware register before it complete the boot process makes
no sense, it will report 0 even if FW is available from internal memory.
Always wait for FW to boot before continuing or we'll unnecessarily try
to load it from nvmem/filesystem and fail.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>