clk: starfive: jh7100: Add CLK_SET_RATE_PARENT to gmac_tx

clk: starfive: jh7100: Add CLK_SET_RATE_PARENT to gmac_tx

This is needed by the dwmac-starfive ethernet driver to set the clock
for 1000, 100 and 10 Mbps links properly.

Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20231219232442.2460166-3-cristian.ciocaltea@collabora.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>