video/console: Resolve several shadow warnings

Resolve shadow warnings that appear in W=2 builds by renaming
the "state" global to "vgastate".

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>