staging: unisys: fix CamelCase parameter in chipset functions

Fix the CamelCase parameter

msgHdr => msg_hdr

In all of the chipset functions. Update all references to use the corrected
name.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>