soc/tegra: Fix an error handling path in tegra_powergate_power_up()

If an error occurs after a successful tegra_powergate_enable_clocks()
call, it must be undone by a tegra_powergate_disable_clocks() call, as
already done in the below and above error handling paths of this function.

Update the 'goto' to branch at the correct place of the error handling
path.

Fixes: a3804512 ("soc/tegra: pmc: Add generic PM domain support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>