staging: rtl8192e: rtl8192e: rtl_pm.c: Remove some unused functions

Removes some functions that are not used anywhere:
rtl8192E_save_state() rtl8192E_enable_wake()

This was partially found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>