rtlwifi: Download firmware as bytes rather than as dwords

The firmware is read from disk as a little-endian byte string. The code
that loads the firmware into the device transfers it as 4-byte quantities.
The routines that write multi-byte quantities on BE hardware assume that
the data are in CPU order, and automatically do the conversion to the LE
order required by the device. As a result, the firmware is transmitted
incorrectly. Rather than do multiple byte swaps on the data, the download
routine is revised to transmit bytes rather than dwords. Although the
number of I/O operations is increased, the firmware is not often loaded.

All drivers have the same bug, and use essentially the same code to
download firmware. These routines have been moved into rtlwifi.

Some CamelCase variables have been renamed.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>