General code modification for mpc7448hpc2 board support.
1. Add 7447A and 7448 processor support.
2. Add the following flags.

CFG_CONFIG_BUS_CLK : If the 74xx bus frequency can be configured dynamically
(such as by switch on board), this flag should be set.

CFG_EXCEPTION_AFTER_RELOCATE: If an exception occurs after the u-boot
relocates to RAM, this flag should be set.

CFG_SERIAL_HANG_IN_EXCEPTION: If the print out function will cause the
system hang in exception, this flag should be set.

There is a design issue for tsi108/109 pci configure  read. When pci scan
the slots, if there is no pci card, the tsi108/9 will cause a machine
check exception for mpc7448 processor.

Signed-off-by: Alexandre Bounine <alexandreb@tundra.com>
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
diff --git a/Makefile b/Makefile
index 62dafc5..e2fb6fd 100644
--- a/Makefile
+++ b/Makefile
@@ -1718,6 +1718,9 @@
 EVB64260_750CX_config:	unconfig
 	@$(MKCONFIG) EVB64260 ppc 74xx_7xx evb64260
 
+mpc7448hpc2_config:  unconfig
+	@./mkconfig $(@:_config=) ppc 74xx_7xx mpc7448hpc2
+
 P3G4_config: unconfig
 	@$(MKCONFIG) $(@:_config=) ppc 74xx_7xx evb64260