Staging: bcm: Remove typedef for _STTARGETDSXBUFFER and call directly.

This patch removes typedef for _STTARGETDSXBUFFER,
changes the name of the struct from
_STTARGETDSXBUFFER to bcm_targetdsx_buffer.
In addition, any calls to the following typedefs
"STTARGETDSXBUFFER, *PSTTARGETDSXBUFFER" are
changed to call the struct directly.

Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>