fbdev/atmel_lcdfb: 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>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-5-tzimmermann@suse.de

drivers/video/fbdev/Kconfig

@@ -713,9 +713,7 @@ config FB_ATMEL
 	depends on FB && OF && HAVE_CLK && HAS_IOMEM
 	depends on HAVE_FB_ATMEL || COMPILE_TEST
 	select FB_BACKLIGHT
-	select FB_CFB_FILLRECT
-	select FB_CFB_COPYAREA
-	select FB_CFB_IMAGEBLIT
+	select FB_IOMEM_HELPERS
 	select FB_MODE_HELPERS
 	select VIDEOMODE_HELPERS
 	help

drivers/video/fbdev/atmel_lcdfb.c

@@ -806,14 +806,12 @@ static int atmel_lcdfb_blank(int blank_mode, struct fb_info *info)
 
 static const struct fb_ops atmel_lcdfb_ops = {
 	.owner		= THIS_MODULE,
+	FB_DEFAULT_IOMEM_OPS,
 	.fb_check_var	= atmel_lcdfb_check_var,
 	.fb_set_par	= atmel_lcdfb_set_par,
 	.fb_setcolreg	= atmel_lcdfb_setcolreg,
 	.fb_blank	= atmel_lcdfb_blank,
 	.fb_pan_display	= atmel_lcdfb_pan_display,
-	.fb_fillrect	= cfb_fillrect,
-	.fb_copyarea	= cfb_copyarea,
-	.fb_imageblit	= cfb_imageblit,
 };
 
 static irqreturn_t atmel_lcdfb_interrupt(int irq, void *dev_id)