To avoid lot of check in stmmac_main for display ring management
and support the GMAC4 chip, the display_ring function is moved
into dedicated descriptor file.
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGiuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>