The ifdef was originally added with the intent that the runtime SoC
detection code, and code to support SoCs other than Tegra20, was only
included if the kernel supported SoCs other than Tegra20. However,
the condition was somewhat backwards and did not achieve this goal.
Simply remove the ifdef to solve this, rather than creating a much more
complex version.

We also fix a typo that caused a build error due to cpu_to_csr_req being
undefined.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
[swarren: rewrote commit description]
Signed-off-by: Stephen Warren <swarren@nvidia.com>