ARM: OMAP2+: Populate DMTIMER errata when using device-tree

Currently the DMTIMER errata flags are not being populated when using
device-tree. Add static platform data to populate errata flags when
using device-tree.

Please note that DMTIMER erratum i767 is applicable to OMAP3-5 devices
as well as AM335x devices.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>