drivers/base/component.c: remove superfluous header files from component.c

component.c hasn't use any macro or function declared in linux/kref.h.
Thus, these files can be removed from component.c safely without
affecting the compilation of the drivers/base/ module
Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
Link: https://lore.kernel.org/r/20210928193849.28717-1-liumh1@shanghaitech.edu.cnSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/component.c

@@ -9,7 +9,6 @@
  */
 #include <linux/component.h>
 #include <linux/device.h>
-#include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>