sysfb: Replace screen_info with sysfb_primary_display

sysfb: Replace screen_info with sysfb_primary_display

Replace the global screen_info with sysfb_primary_display of type
struct sysfb_display_info. Adapt all users of screen_info.

Instances of screen_info are defined for x86, loongarch and EFI,
with only one instance compiled into a specific build. Replace all
of them with sysfb_primary_display.

All existing users of screen_info are updated by pointing them to
sysfb_primary_display.screen instead. This introduces some churn to
the code, but has no impact on functionality.

Boot parameters and EFI config tables are unchanged. They transfer
screen_info as before. The logic in EFI's alloc_screen_info() changes
slightly, as it now returns the screen field of sysfb_primary_display.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci/
Reviewed-by: Richard Lyu <richard.lyu@suse.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>