fbdev/wm8505fb: Initialize fb_ops to fbdev I/O-memory helpers

Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in DMA-able address space. This explictily
sets the read/write, draw and mmap callbacks to the correct default
implementation. Also select the necessary helpers in Kconfig.

Fbdev drivers sometimes rely on the callbacks being NULL for a
default implementation to be invoked; hence requireing the I/O
helpers to be built in any case. Setting all callbacks in all
drivers explicitly will allow to make the I/O helpers optional.
This benefits systems that do not use these functions.

Set the callbacks via macros. No functional changes.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-24-tzimmermann@suse.de

drivers/video/fbdev/Kconfig

@@ -1480,6 +1480,7 @@ config FB_WM8505
 	select FB_SYS_FILLRECT if (!FB_WMT_GE_ROPS)
 	select FB_SYS_COPYAREA if (!FB_WMT_GE_ROPS)
 	select FB_SYS_IMAGEBLIT
+	select FB_SYS_FOPS
 	select FB_MODE_HELPERS
 	select VIDEOMODE_HELPERS
 	help

drivers/video/fbdev/wm8505fb.c

@@ -248,6 +248,7 @@ static int wm8505fb_blank(int blank, struct fb_info *info)
 
 static const struct fb_ops wm8505fb_ops = {
 	.owner		= THIS_MODULE,
+	__FB_DEFAULT_DMAMEM_OPS_RDWR,
 	.fb_set_par	= wm8505fb_set_par,
 	.fb_setcolreg	= wm8505fb_setcolreg,
 	.fb_fillrect	= wmt_ge_fillrect,
@@ -256,6 +257,7 @@ static const struct fb_ops wm8505fb_ops = {
 	.fb_sync	= wmt_ge_sync,
 	.fb_pan_display	= wm8505fb_pan_display,
 	.fb_blank	= wm8505fb_blank,
+	__FB_DEFAULT_IOMEM_OPS_MMAP,
 };
 
 static int wm8505fb_probe(struct platform_device *pdev)