ARM: OMAP: Remove omap_init_consistent_dma_size()

The only thing omap_init_consistent_dma_size() does is increase the
consistent DMA size if CONFIG_FB_OMAP_CONSISTENT_DMA_SIZE is defined.
Increasing the consistent DMA size should no longer be needed with CMA
in place.

This patch removes omap_init_consistent_dma_size() and also
arch/arm/mach-omap2/io.c:omap_common_init_early() which becomes an empty
function.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
[tony@atomide.com: updated for moved dma.h]
Signed-off-by: Tony Lindgren <tony@atomide.com>