clk: tegra: probe deferral error reporting

Actually report the error code from devm_regulator_get() which may as
well just be a probe deferral.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>