fbdev/ocfb: Use fbdev I/O helpers

Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.

The macro and token set the currently selected values, so there is
no functional change.

v3:
	* use _IOMEM_ in commit message
v2:
	* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-28-tzimmermann@suse.de

drivers/video/fbdev/Kconfig

@@ -672,9 +672,7 @@ config FB_PVR2
 config FB_OPENCORES
 	tristate "OpenCores VGA/LCD core 2.0 framebuffer support"
 	depends on FB && HAS_DMA
-	select FB_CFB_FILLRECT
-	select FB_CFB_COPYAREA
-	select FB_CFB_IMAGEBLIT
+	select FB_IOMEM_HELPERS
 	help
 	  This enables support for the OpenCores VGA/LCD core.
 

drivers/video/fbdev/ocfb.c

@@ -287,10 +287,8 @@ static int ocfb_init_var(struct ocfb_dev *fbdev)
 
 static const struct fb_ops ocfb_ops = {
 	.owner		= THIS_MODULE,
+	FB_DEFAULT_IOMEM_OPS,
 	.fb_setcolreg	= ocfb_setcolreg,
-	.fb_fillrect	= cfb_fillrect,
-	.fb_copyarea	= cfb_copyarea,
-	.fb_imageblit	= cfb_imageblit,
 };
 
 static int ocfb_probe(struct platform_device *pdev)