ARM: tegra: Add Tegra AHB driver

Tegra AHB Bus conforms to the AMBA Specification (Rev 2.0) Advanced
High-performance Bus (AHB) architecture.

The AHB Arbiter controls AHB bus master arbitration. This effectively
forms a second level of arbitration for access to the memory
controller through the AHB Slave Memory device. The AHB pre-fetch
logic can be configured to enhance performance for devices doing
sequential access. Each AHB master is assigned to either the high or
low priority bin. Both Tegra20/30 have this AHB bus.

Some of configuration params could be passed from DT too if needed.

Signed-off-by: Hiroshi DOYU <hdoyu@nvidia.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

drivers/Makefile

@@ -18,7 +18,7 @@ obj-$(CONFIG_SFI)		+= sfi/
 # PnP must come after ACPI since it will eventually need to check if acpi
 # was used and do nothing if so
 obj-$(CONFIG_PNP)		+= pnp/
-obj-$(CONFIG_ARM_AMBA)		+= amba/
+obj-y				+= amba/
 # Many drivers will want to use DMA so this has to be made available
 # really early.
 obj-$(CONFIG_DMA_ENGINE)	+= dma/