ARM: OMAP: change get_context_loss_count ret value to int

get_context_loss_count functions return context loss count as u32, and
zero means an error. However, zero is also returned when context has
never been lost and could also be returned when the context loss count
has wrapped and goes to zero.

Change the functions to return an int, with negative value meaning an
error.

OMAP HSMMC code uses omap_pm_get_dev_context_loss_count(), but as the
hsmmc code handles the returned value as an int, with negative value
meaning an error, this patch actually fixes hsmmc code also.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
[tony@atomide.com: updated to fix a warning with recent dmtimer changes]
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/plat-omap/include/plat/omap-pm.h b/arch/arm/plat-omap/include/plat/omap-pm.h
index 0840df8..67faa7b 100644
--- a/arch/arm/plat-omap/include/plat/omap-pm.h
+++ b/arch/arm/plat-omap/include/plat/omap-pm.h
@@ -342,9 +342,9 @@
  * driver must restore device context.   If the number of context losses
  * exceeds the maximum positive integer, the function will wrap to 0 and
  * continue counting.  Returns the number of context losses for this device,
- * or zero upon error.
+ * or negative value upon error.
  */
-u32 omap_pm_get_dev_context_loss_count(struct device *dev);
+int omap_pm_get_dev_context_loss_count(struct device *dev);
 
 void omap_pm_enable_off_mode(void);
 void omap_pm_disable_off_mode(void);