clk: sifive: prci: fix module autoloading

Add MODULE_DEVICE_TABLE(), so modules could be properly autoloaded
based on the alias from of_device_id table.  Clocks are considered core
components, so usually they are built-in, however these can be built and
used as modules on some generic kernel.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240604130531.170371-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Stephen Boyd <sboyd@kernel.org>