MAINTAINERS: add pxa dma driver to pxa architecture

Add the pxa dma driver as maintained by the pxa architecture
maintainers, as it is part of the core IP.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

MAINTAINERS

@@ -7937,6 +7937,7 @@ T:	git git://github.com/hzhuang1/linux.git
 T:	git git://github.com/rjarzmik/linux.git
 S:	Maintained
 F:	arch/arm/mach-pxa/
+F:	drivers/dma/pxa*
 F:	drivers/pcmcia/pxa2xx*
 F:	drivers/spi/spi-pxa2xx*
 F:	drivers/usb/gadget/udc/pxa2*