wimax/i2400m: Let device's status reports change the device state

Currently __i2400m_dev_start was forcing, after uploading firmware and
doing a few checks to WIMAX_ST_UNINITIALIZED.

This can be overriding state changes that the device might have caused
by sending reports; thus it makes more sense to remove it and let the
device update the status on its own by sending reports.

Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>