ARM: remove unused VIDEOLFB ATAG

ATAG_VIDEOLFB is not used anywhere.
The belowing warning is occurred due to this ATAG.

[    0.000000] Ignoring unrecognised tag 0x54410008

This patch fixed it.

Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Martin Krause <Martin.Krause@tqs.de>