Staging: bcm: Fix a coding style error reported by checkpatch.pl

Tool checkpatch.pl reported the following error: extern struct class *bcm_class;"
declaration not allowed in .c files. Therefore, I move this declaration into
the header "headers.h" file.

Signed-off-by: Kevin McKinney <[e-mail]>
Reviewed-by: Dan Carpenter <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/bcm/Bcmchar.c

···
 	.llseek = no_llseek,
 };
 
-extern struct class *bcm_class;
-
 int register_control_device_interface(PMINI_ADAPTER Adapter)
 {
 

drivers/staging/bcm/headers.h

···
 #define DRV_VERSION	VER_FILEVERSION_STR
 #define PFX		DRV_NAME " "
 
+extern struct class *bcm_class;
+
 #endif