net: stmmac: dwc-qos-eth: Fix typo in DT bindings parsing

According to DT bindings documentation we are expecting a
property called "snps,read-requests" but we are parsing
instead a property called "read,read-requests".

This is clearly a typo. Fix it.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>