drivers: dma-removed: fix data type to hold base address

removed_region->base should be phy_addr_t type as it
directly holds physical memory address. Fix it.

Change-Id: I80d49d209cf0f319b7a468697387d23e6bcb1b98
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>