serial: tegra: handle clk prepare error in tegra_uart_hw_init()

In tegra_uart_hw_init(), the return value of clk_prepare_enable() should
be checked since it might fail.

Fixes: e9ea096d ("serial: tegra: add serial driver")
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Link: https://lore.kernel.org/r/20230817105406.228674-1-yiyang13@huawei.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>