net: stmmac: Limit FIFO size by hardware capability

net: stmmac: Limit FIFO size by hardware capability

Tx/Rx FIFO size is specified by the parameter "{tx,rx}-fifo-depth" from
stmmac_platform layer.

However, these values are constrained by upper limits determined by the
capabilities of each hardware feature. There is a risk that the upper
bits will be truncated due to the calculation, so it's appropriate to
limit them to the upper limit values and display a warning message.

This only works if the hardware capability has the upper limit values.

Fixes: e7877f52fd4a ("stmmac: Read tx-fifo-depth and rx-fifo-depth from the devicetree")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: Yanteng Si <si.yanteng@linux.dev>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>