qemu: switch to '-vga std' emulated hardware from vmware/cirrus for x86/mips

qemu: switch to '-vga std' emulated hardware from vmware/cirrus for x86/mips

This is the qemu default since qemu 2.2, is generally supported better,
and is recommended by upstream. It also has already been in use for arm/risc
and ovmf.

Additional information:
https://bugzilla.yoctoproject.org/show_bug.cgi?id=13466
https://www.kraxel.org/blog/2014/10/qemu-using-cirrus-considered-harmful/

'-vga virtio' emulated hardware remains in use when virgl is enabled via a runqemu override.

Also, adjust the error whitelist, as there is a number of new messages
coming from the drivers that are not actual errors.

Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>