rtlwifi: rtl8192cu: Fix endianian issues

Driver rtlwifi fails on a big-endian host.

These changes have been tested on a Mac PowerBook G4, which has
a PPC processor.

Although this patch touches some of the code that will affect endian
issues on PCI hardware through drivers rtl8192ce, rtl8192se, and
rtl8192de, these have not been tested due to lack of suitable hardware.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>