Added information message when using the SRAM in mv643xx_eth_probe()

Signed-off-by: Nicolas DET <det.nicolas@free.fr>
Signed-off-by: Sven Luther <sl@bplan-gmbh.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>