staging: rtl8712: remove (most of) enum WIFI_FRAME_TYPE

The values defined in enum WIFI_FRAME_TYPE are the same the #define
IEEE80211_FTYPE_xxx from <linux/ieee80211.h>

Use these values to avoid code duplication.

WIFI_QOS_DATA_TYPE is a bit more tricky and doesn't have a direct
equivalence in <linux/ieee80211.h>. So leave this one as-is for now.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/e009a4ee6429a3f79742f9a912e3f6a650fb33ed.1617911201.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>