rtl8192e: delete local copy of iee80211 reason codes.

This driver has a copy of the standard reason codes from the file
<linux/ieee80211.h> but with slightly different name fields.

Delete the local copy and remap the only two use cases onto the names
used by the global implementation with the same values.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>