This reverts commit 510bb595 "ARM: tegra: add cpu_disable for hotplug".

The Tegra114 support CPU0 hotplug function in HW physically, but it needs
other software to make it work normally after we add CPU idle power down
mode support. So remove them for now.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>