fbdev/grvga: 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/20230803184034.6456-18-tzimmermann@suse.de

drivers/video/fbdev/Kconfig

@@ -64,9 +64,7 @@ config FB_MACMODES
 config FB_GRVGA
 	tristate "Aeroflex Gaisler framebuffer support"
 	depends on FB && SPARC
-	select FB_CFB_FILLRECT
-	select FB_CFB_COPYAREA
-	select FB_CFB_IMAGEBLIT
+	select FB_IOMEM_HELPERS
 	help
 	  This enables support for the SVGACTRL framebuffer in the GRLIB IP library from Aeroflex Gaisler.
 

drivers/video/fbdev/grvga.c

@@ -253,13 +253,11 @@ static int grvga_pan_display(struct fb_var_screeninfo *var,
 
 static const struct fb_ops grvga_ops = {
 	.owner          = THIS_MODULE,
+	FB_DEFAULT_IOMEM_OPS,
 	.fb_check_var   = grvga_check_var,
 	.fb_set_par	= grvga_set_par,
 	.fb_setcolreg   = grvga_setcolreg,
 	.fb_pan_display = grvga_pan_display,
-	.fb_fillrect	= cfb_fillrect,
-	.fb_copyarea	= cfb_copyarea,
-	.fb_imageblit	= cfb_imageblit
 };
 
 static int grvga_parse_custom(char *options,