riscv: Fix kernel time_init()

[ Upstream commit 11f4c2e940e2f317c9d8fb5a79702f2a4a02ff98 ]

If of_clk_init() is not called in time_init(), clock providers defined
in the system device tree are not initialized, resulting in failures for
other devices to initialize due to missing clocks.
Similarly to other architectures and to the default kernel time_init()
implementation, call of_clk_init() before executing timer_probe() in
time_init().

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>