staging:rtl8192u: Rename PHY_SetRF8256Bandwidth() - Style

Rename the function PHY_SetRF8256Bandwidth() to
phy_set_rf8256_bandwidth(). This change clears the checkpatch issue
with CamelCase naming.

The parameter Bandwidth has been renamed to bandwidth, for the
same reason.

Additionally a new line has been added to the parameter list of the
function declaration in r8190_rtl8256.h to truncate the line length
to the checkpatch limit.

These changes are simple coding style changes which should have no
impact on runtime code execution.

Signed-off-by: John Whitmore <johnfwhitmore@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>