drm: Remove plane hsub/vsub alignment requirement for core helpers

The drm_format_info_plane_{height,width} functions was implemented using
regular division for the plane size calculation, which cause issues [1][2]
when used on contexts where the dimensions are misaligned with relation
to the subsampling factors. So, replace the regular division by the
DIV_ROUND_UP macro.

This allows these functions to be used in more drivers, making further
work to bring more core presence on them possible.

[1] http://patchwork.freedesktop.org/patch/msgid/[email protected]
[2] https://patchwork.freedesktop.org/patch/msgid/[email protected]

Signed-off-by: Carlos Eduardo Gallo Filho <[email protected]>
Reviewed-by: André Almeida <[email protected]>
Signed-off-by: Thomas Zimmermann <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: gcarlos64

include/drm/drm_fourcc.h

@@ -22,6 +22,7 @@
 #ifndef __DRM_FOURCC_H__
 #define __DRM_FOURCC_H__
 
+#include <linux/math.h>
 #include <linux/types.h>
 #include <uapi/drm/drm_fourcc.h>
 
@@ -279,7 +280,7 @@ int drm_format_info_plane_width(const struct drm_format_info *info, int width,
 	if (plane == 0)
 		return width;
 
-	return width / info->hsub;
+	return DIV_ROUND_UP(width, info->hsub);
 }
 
 /**
@@ -301,7 +302,7 @@ int drm_format_info_plane_height(const struct drm_format_info *info, int height,
 	if (plane == 0)
 		return height;
 
-	return height / info->vsub;
+	return DIV_ROUND_UP(height, info->vsub);
 }
 
 const struct drm_format_info *__drm_format_info(u32 format);