PowerPC: drop some 74xx_7xx boards and related code

The file  board/Marvell/include/mv_gen_reg.h  is incompatible with
the GPL (see for example the "MARVELL RESERVES THE RIGHT AT ITS SOLE
DISCRETION TO REQUEST THAT THIS CODE BE IMMEDIATELY RETURNED TO
MARVELL" clause).  As this cannot be fixed, we remove the file and all
code that depends on it.  Fortunately this only affects some very old
boards that have long reached EOL:
	CPCI750
	DB64360
	DB64460
	p3m750
	p3m7448

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Reinhard Arlt <reinhard.arlt@esd-electronics.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Roger Meier <r.meier@siemens.com>
diff --git a/drivers/net/eepro100.c b/drivers/net/eepro100.c
index 1e4ea0c..a23a585 100644
--- a/drivers/net/eepro100.c
+++ b/drivers/net/eepro100.c
@@ -230,7 +230,7 @@
 static int eepro100_recv (struct eth_device *dev);
 static void eepro100_halt (struct eth_device *dev);
 
-#if defined(CONFIG_E500) || defined(CONFIG_DB64360) || defined(CONFIG_DB64460)
+#if defined(CONFIG_E500)
 #define bus_to_phys(a) (a)
 #define phys_to_bus(a) (a)
 #else