serial: tegra: Fix compilation error

Fix compilation error, by adding the correct header file
for Tegra clocks.

Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed