OMAP2/3: DMA errata correction

This errata is valid for:
OMAP2420 Errata 1.85 Impacts all 2420 ES rev
OMAP2430 Errata 1.10 Impacts only ES1.0
Description: DMA may hang when several channels are used in parallel
OMAP3430: Not impacted, so remove the errata fix for omap3

Fixed issue reported on cpu_is_omap24xx check reported by Nishant Kamat

Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>
Reviewed-by: Nishant Kamat <nskamat@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>