ARM: tegra: export apb dma readl/writel

Export APB DMA readl and writel. These are needed because we can't
access the fuses directly on Tegra20 without potentially causing a
system hang. Also have the APB DMA readl and writel return an error in
case of a read failure instead of just returning zero or ignore write
failures.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --cc arch/arm/mach-tegra/apbio.c
Simple merge

diff --cc include/soc/tegra/fuse.h
Simple merge