ARM: dts: Removing pdma for exynos5440

Since the pdma works only in secure mode, accessing the same
in hypervisor mode gives an abort. As we are not using pdma
anywhere, removing the same.

Signed-off-by: Giridhar Maruthy <giridhar.m@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>