net: emaclite: Adopt clock support

net: emaclite: Adopt clock support

Adapt to use the clock framework. Add s_axi_aclk clock from the processor
bus clock domain and make clk optional to keep DTB backward compatibility.

Signed-off-by: Abin Joseph <abin.joseph@amd.com>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/1728491303-1456171-4-git-send-email-radhey.shyam.pandey@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>