ARM: OMAP: Remove calls to SRAM allocations for framebuffer

This assumes fixed mappings which will not work once we move
to use ioremap_exec(). It seems that these are currently
not in use, or in use for some out of tree corner cases.

If SRAM support for framebuffer is wanted, it should be done
with ioremap in the driver.

Note that further removal of the code can now be done,
but that can be done seprately by the driver maintainers.

Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>