Currently we enable CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER=y.  This is
essentially useful only for the i915 fastboot.  But we don't enable i915
fastboot as default, and we even keep the plymouth boot splash.

The deferred console takeover has an obvious drawback that it doesn't
initialize the graphics screen.  On a bare metal, it'll lead to the BIOS boot
logo again, which is confusing.  And more badly, on KVM, it just shows some
garbage.

So, for our default setup, it's better to turn off the deferred takeover.

However, one problem is that, if we set
CONFIG_FRAMEBUFER_CONSOLE_DEFERRED_TAKEOVER=n, the deferred takeover behavior
can't be enabled dynamically since the option disables at the compile time.
So, if user wants to re-enable the deferred takeover together with
i915.fastboot=1, it won't work unless you recompile the kernel.

The deferred takeover can be disabled via boot option "fbcon=nodefer", too.
But it's not practical to set this.  Maybe we'd need a patch to provide the
default value in addition to the existing
CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER...