ARM: tegra: provide clock aliases for AHUB configlink

The Tegra30 AHUB driver must call tegra_periph_reset_deassert() for all
devices on the AHUB's configlink bus. The AHUB driver must be able to
call clk_get_sys() to retrieve the clock parameter for this function.
Add the necessary clock aliases to allow this.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Olof Johansson <olof@lixom.net>