SPARC/LEON3: Added GRETH Ethernet 10/100/1000 driver.

GRETH is an Ethernet 10/100 or 10/100/1000 MAC with out without
a debug link (EDCL). The GRETH core is documented in GRIP.pdf
available at www.gaisler.com.

If the GRETH has GigaBit support (GBIT, Scatter gather, checksum
offloading etc.) can be determined by a bit in the control register.
The GBIT MAC is supported by operating in GRTEH 10/100 legacy mode.

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/net/eth.c b/net/eth.c
index 16a6dcb..3b86f87 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -60,6 +60,7 @@
 extern int uec_initialize(int);
 extern int bfin_EMAC_initialize(bd_t *);
 extern int atstk1000_eth_initialize(bd_t *);
+extern int greth_initialize(bd_t *);
 extern int atngw100_eth_initialize(bd_t *);
 extern int mcffec_initialize(bd_t*);
 extern int mcdmafec_initialize(bd_t*);
@@ -275,6 +276,9 @@
 #if defined(CONFIG_ATSTK1000)
 	atstk1000_eth_initialize(bis);
 #endif
+#if defined(CONFIG_GRETH)
+	greth_initialize(bis);
+#endif
 #if defined(CONFIG_ATNGW100)
 	atngw100_eth_initialize(bis);
 #endif