acpi-video-detect: Move acpi_osi_is_win8 to osl.c

acpi_osi_is_win8 needs access to acpi_gbl_osi_data which is not exported,
so move it to osl.c. Alternatively we could export acpi_gbl_osi_data but
that seems undesirable.

This allows video_detect.c to be build as a module, besides that
acpi_osi_is_win8() is something which does not really belong in
video_detect.c in the first place.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/internal.h

@@ -181,13 +181,6 @@ static inline int suspend_nvs_save(void) { return 0; }
 static inline void suspend_nvs_restore(void) {}
 #endif
 
-/*--------------------------------------------------------------------------
-					Video
-  -------------------------------------------------------------------------- */
-#if defined(CONFIG_ACPI_VIDEO) || defined(CONFIG_ACPI_VIDEO_MODULE)
-bool acpi_osi_is_win8(void);
-#endif
-
 /*--------------------------------------------------------------------------
 				Device properties
   -------------------------------------------------------------------------- */

drivers/acpi/osl.c

@@ -1684,6 +1684,12 @@ int acpi_resources_are_enforced(void)
 }
 EXPORT_SYMBOL(acpi_resources_are_enforced);
 
+bool acpi_osi_is_win8(void)
+{
+	return acpi_gbl_osi_data >= ACPI_OSI_WIN_8;
+}
+EXPORT_SYMBOL(acpi_osi_is_win8);
+
 /*
  * Deallocate the memory for a spinlock.
  */

drivers/acpi/video_detect.c

@@ -178,12 +178,6 @@ static void acpi_video_caps_check(void)
 		acpi_video_get_capabilities(NULL);
 }
 
-bool acpi_osi_is_win8(void)
-{
-	return acpi_gbl_osi_data >= ACPI_OSI_WIN_8;
-}
-EXPORT_SYMBOL(acpi_osi_is_win8);
-
 /* Promote the vendor interface instead of the generic video module.
  * This function allow DMI blacklists to be implemented by externals
  * platform drivers instead of putting a big blacklist in video_detect.c

include/linux/acpi.h

@@ -266,6 +266,7 @@ static inline int acpi_video_backlight_support(void)
 extern int acpi_blacklisted(void);
 extern void acpi_dmi_osi_linux(int enable, const struct dmi_system_id *d);
 extern void acpi_osi_setup(char *str);
+extern bool acpi_osi_is_win8(void);
 
 #ifdef CONFIG_ACPI_NUMA
 int acpi_get_node(acpi_handle handle);