omap1: DMA: move LCD related code from plat-omap to mach-omap1

omap1: DMA: move LCD related code from plat-omap to mach-omap1

All of the LCD DMA code in plat-omap/dma.c appears to be OMAP1-only (and
apparently only is available on a subset of OMAP1 chips).

Move this code to mach-omap1/lcd_dma.c.

Tested on OMAP1510 Amstrad Delta.
Compile-tested with omap_generic_2420_defconfig.

Reported-by: Paul Walmsley <[email protected]>
Signed-off-by: Janusz Krzysztofik <[email protected]>
Reviewed-by: Paul Walmsley <[email protected]>
Signed-off-by: Tony Lindgren <[email protected]>