drm/exynos: exynos_drm.h header file fixes

First of all #ifdef __KERNEL__ was added to exynos_drm.h to
mark the part that should be left out of userspace.
Secondly exynos_drm.h was added to include/drm/Kbuild, so it
will be included when doing make headers_install.
Signed-off-by: NKamil Debski <k.debski@samsung.com>
Signed-off-by: NInki Dae <inki.dae@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>

include/drm/Kbuild

@@ -2,6 +2,7 @@ header-y += drm.h
 header-y += drm_fourcc.h
 header-y += drm_mode.h
 header-y += drm_sarea.h
+header-y += exynos_drm.h
 header-y += i810_drm.h
 header-y += i915_drm.h
 header-y += mga_drm.h

include/drm/exynos_drm.h

@@ -97,6 +97,8 @@ struct drm_exynos_plane_set_zpos {
 #define DRM_IOCTL_EXYNOS_PLANE_SET_ZPOS	DRM_IOWR(DRM_COMMAND_BASE + \
 		DRM_EXYNOS_PLANE_SET_ZPOS, struct drm_exynos_plane_set_zpos)
 
+#ifdef __KERNEL__
+
 /**
  * A structure for lcd panel information.
  *
@@ -152,4 +154,5 @@ struct exynos_drm_hdmi_pdata {
 	unsigned int			bpp;
 };
 
-#endif
+#endif	/* __KERNEL__ */
+#endif	/* _EXYNOS_DRM_H_ */