rtlwifi: rtl8192de: Fix phy-based version calculation

Commit d83579e2 incorporated some
changes from the vendor driver that made it newly important that the
calculated hardware version correctly include the CHIP_92D bit, as all
of the IS_92D_* macros were changed to depend on it.  However, this bit
was being unset for dual-mac, dual-phy devices.  The vendor driver
behavior was modified to not do this, but unfortunately this change was
not picked up along with the others.  This caused scanning in the 2.4GHz
band to be broken, and possibly other bugs as well.

This patch brings the version calculation logic in parity with the
vendor driver in this regard, and in doing so fixes the regression.
However, the version calculation code in general continues to be largely
incoherent and messy, and needs to be cleaned up.

Signed-off-by: Forest Bond <forest.bond@rapidrollout.com>
Cc: Stable <stable@vger.kernel.org> [v3.2+]
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>