ARM: tegra: apbio: remove support of legacy DMA driver based access

Remove the support code which uses the legacy APB DMA driver
for accessing the apbio register.
The driver will use the dmaengine based APB DMA driver for
accessing apbio register.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>