soc: qcom: ocmem: add missing includes

The kbuild bot reported the following compiler errors when compiling on
MIPS with CONFIG_QCOM_OCMEM disabled:

  In file included from <command-line>:0:0:
  >> include/soc/qcom/ocmem.h:43:49: warning: 'struct device' declared
     inside parameter list will not be visible outside of this
     definition or declaration
      static inline struct ocmem *of_get_ocmem(struct device *dev)
                                                      ^~~~~~
     include/soc/qcom/ocmem.h: In function 'of_get_ocmem':
  >> include/soc/qcom/ocmem.h:45:9: error: implicit declaration of
     function 'ERR_PTR' [-Werror=implicit-function-declaration]
       return ERR_PTR(-ENODEV);
              ^~~~~~~
  >> include/soc/qcom/ocmem.h:45:18: error: 'ENODEV' undeclared (first
     use in this function)
       return ERR_PTR(-ENODEV);

Add the proper includes to fix the compiler errors.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reported-by: kbuild test robot <lkp@intel.com>
Tested-by: Gabriel Francisco <frc.gabriel@gmail.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>

include/soc/qcom/ocmem.h

@@ -9,6 +9,9 @@
  * Copyright (C) 2015 Red Hat. Author: Rob Clark <robdclark@gmail.com>
  */
 
+#include <linux/device.h>
+#include <linux/err.h>
+
 #ifndef __OCMEM_H__
 #define __OCMEM_H__