misc: implement Tegra CAR core driver

The Tegra CAR (Clock And Reset) module provides control of most clocks
and reset signals within the Tegra SoC. This change implements a driver
for this module. However, since the module implements multiple kinds of
services (clocks, resets, perhaps more), all this driver does is bind
various sub-devices, which in turn provide the real services. This driver
is essentially an "MFD" (Multi-Function Device) in Linux kernel speak.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>