This VDMA  is a soft ip, which can be programmed to support
32 bit addressing or greater than 32 bit addressing.

When the VDMA ip is configured for 32 bit address space
the buffer address is specified by a single register
(0x5C for MM2S and 0xAC for S2MM channel).

When the  VDMA core is configured for an address space greater
than 32 then each buffer address is specified by a combination of
two registers.

The first register specifies the LSB 32 bits of address,
while the next register specifies the MSB 32 bits of address.

For example, 5Ch will specify the LSB 32 bits while 60h will
specify the MSB 32 bits of the first start address.
So we need to program two registers at a time.

This patch adds the 64 bit addressing support to the vdma driver.
Signed-off-by: Anurag Kumar Vulisha <anuragku@xilinx.com>
Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>