stmmac: fix the EEE LPI Macro definitions.

This patch is to fix the definition of macros for EEE otherwise the LPI TX/RX
entry/exit cannot be properly managed.

Signed-off-by: Nandini Sharma <nandini.sharma@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>