PCI/VGA: Select SCREEN_INFO on X86

commit 337bf13a ("PCI/VGA: Replace vga_is_firmware_default() with a
screen info check") introduced an implicit dependency upon SCREEN_INFO by
removing the open coded implementation.

If a user didn't have CONFIG_SCREEN_INFO set, vga_is_firmware_default()
would now return false.  SCREEN_INFO is only used on X86 so add a
conditional select for SCREEN_INFO to ensure that the VGA arbiter works as
intended.

Fixes: 337bf13a ("PCI/VGA: Replace vga_is_firmware_default() with a screen info check")
Reported-by: Eric Biggers <ebiggers@kernel.org>
Closes: https://lore.kernel.org/linux-pci/20251012182302.GA3412@sol/


Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Eric Biggers <ebiggers@kernel.org>
Link: https://patch.msgid.link/20251013220829.1536292-1-superm1@kernel.org