net: stmmac: Let descriptor code get skbuff address

Stop using if conditions depending on the GMAC version for getting the
descriptor skbuff address and use instead a helper implemented in the
descriptor files.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Vitor Soares <soares@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 06b5e5b1..f499a7f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -79,6 +79,8 @@ struct stmmac_desc_ops {
 	void (*display_ring)(void *head, unsigned int size, bool rx);
 	/* set MSS via context descriptor */
 	void (*set_mss)(struct dma_desc *p, unsigned int mss);
+	/* get descriptor skbuff address */
+	void (*get_addr)(struct dma_desc *p, unsigned int *addr);
 	/* set descriptor skbuff address */
 	void (*set_addr)(struct dma_desc *p, dma_addr_t addr);
 	/* clear descriptor */
@@ -127,6 +129,8 @@ struct stmmac_desc_ops {
 	stmmac_do_void_callback(__priv, desc, display_ring, __args)
 #define stmmac_set_mss(__priv, __args...) \
 	stmmac_do_void_callback(__priv, desc, set_mss, __args)
+#define stmmac_get_desc_addr(__priv, __args...) \
+	stmmac_do_void_callback(__priv, desc, get_addr, __args)
 #define stmmac_set_desc_addr(__priv, __args...) \
 	stmmac_do_void_callback(__priv, desc, set_addr, __args)
 #define stmmac_clear_desc(__priv, __args...) \