[PATCH] media: atomisp: fix Wvisiblity warning

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

Some randconfig builds include ia_css_firmware.h without first
including linux/device.h:

In file included from atomisp/pci/mmu/sh_mmu_mrfld.c:23:
In file included from atomisp/pci/atomisp_compat.h:22:
In file included from atomisp/pci/atomisp_compat_css20.h:24:
In file included from atomisp/pci/ia_css.h:28:
In file included from atomisp/pci/ia_css_control.h:25:
drivers/staging/media/atomisp//pci/ia_css_firmware.h:52:29: error: declaration of 'struct device' will not be visible outside of this function [-Werror,-Wvisibility]

Add a forward declaration to avoid the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/staging/media/atomisp/pci/ia_css_firmware.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/media/atomisp/pci/ia_css_firmware.h b/drivers/staging/media/atomisp/pci/ia_css_firmware.h
index edab72256494..38f0408947d1 100644
--- a/drivers/staging/media/atomisp/pci/ia_css_firmware.h
+++ b/drivers/staging/media/atomisp/pci/ia_css_firmware.h
@@ -30,6 +30,8 @@ struct ia_css_fw {
 	unsigned int bytes; /** length in bytes of firmware data */
 };
 
+struct device;
+
 /* @brief Loads the firmware
  * @param[in]	env		Environment, provides functions to access the
  *				environment in which the CSS code runs. This is
-- 
2.29.2