staging: rtl8188eu: remove unused function declarations

There are no definitions of odm_DIGbyRSSI_LPS(), ODM_PhyStatusQuery()
and ODM_MacStatusQuery() in the driver code. So remove the unused
declarations from the headers odm.h and odm_hwconfig.h.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>