ARM: 5622/1: at91: at91sam9g45 headers: DMA peripheral identifiers

It adds DMA peripheral identifiers for hardware handshaking interface. It will
be used in platform code.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>