rtl8xxxu: Reorg more code to match the flow of the 8192eu vendor driver

This further reorganizes the init code flow to match that of the
8192eu vendor driver. This helps diffing the register write log
against that of the vendor driver.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>