fu540: dtsi: add reset producer and consumer entries

The resets to DDR and ethernet sub-system are connected to
PRCI device reset control register, these reset signals
are active low and are held low at power-up. Add these reset
producer and consumer details needed by the reset driver.

Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Reviewed-by: Pragnesh Patel <pragnesh.patel@sifive.com>
Reviewed-by: Bin Meng <bin.meng@windriver.com>