staging: fsl-mc: drop unused forward declaration

This forward declaration of "struct fsl_mc_resource" is of no use so
drop it.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/fsl-mc/include/mc-sys.h

@@ -46,7 +46,6 @@
  */
 #define FSL_MC_IO_ATOMIC_CONTEXT_PORTAL	0x0001
 
-struct fsl_mc_resource;
 struct mc_command;
 
 /**