parisc/stifb: Fix fb_is_primary_device() only available with CONFIG_FB_STI

stable inclusion
from stable-v5.10.127
commit a1c902349ad5656903589d672ad163a23a2a99b4
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5XDDK

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a1c902349ad5656903589d672ad163a23a2a99b4



--------------------------------

commit 1d0811b0 upstream.

Fix this build error noticed by the kernel test robot:

drivers/video/console/sticore.c:1132:5: error: redefinition of 'fb_is_primary_device'
 arch/parisc/include/asm/fb.h:18:19: note: previous definition of 'fb_is_primary_device'

Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: kernel test robot <lkp@intel.com>
Cc: stable@vger.kernel.org   # v5.10+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>