Hi,

It's probably a bug fix that unveils the link errors.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   da2f6aba4a21f8da3331e5251a117c52764da579
commit: f69405ce6c0fc9f4a039011007371b31f80b470d openrisc: include: asm: Kbuild: add default "vga.h"
date:   2 years, 8 months ago
config: openrisc-alldefconfig (attached as .config)
compiler: or32-linux-gcc (GCC) 4.5.1-or32-1.0rc1
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout f69405ce6c0fc9f4a039011007371b31f80b470d
        # save the attached .config to linux build tree
        make.cross ARCH=openrisc 

All errors (new ones prefixed by >>):

   drivers/built-in.o: In function `vgacon_save_screen':
>> vgacon.c:(.text+0x20e0): undefined reference to `screen_info'
   vgacon.c:(.text+0x20e8): undefined reference to `screen_info'
   drivers/built-in.o: In function `vgacon_init':
   vgacon.c:(.text+0x284c): undefined reference to `screen_info'
   vgacon.c:(.text+0x2850): undefined reference to `screen_info'
   drivers/built-in.o: In function `vgacon_startup':
   vgacon.c:(.text+0x28d8): undefined reference to `screen_info'
   drivers/built-in.o:vgacon.c:(.text+0x28f0): more undefined references to `screen_info' follow

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