ppc4xx: Add bootstrap command for AMCC Sequoia (440EPx) eval board

This patch adds a board command to configure the I2C bootstrap EEPROM
values. Right now 533 and 667MHz are supported for booting either via NOR
or NAND FLASH. Here the usage:

=> bootstrap 533 nor        ;to configure the board for 533MHz NOR booting
=> bootstrap 667 nand       ;to configure the board for 667MHz NNAND booting

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/board/amcc/sequoia/Makefile b/board/amcc/sequoia/Makefile
index 06ef7f9..e1c9ad4 100644
--- a/board/amcc/sequoia/Makefile
+++ b/board/amcc/sequoia/Makefile
@@ -25,7 +25,7 @@
 
 LIB	= $(obj)lib$(BOARD).a
 
-COBJS	= $(BOARD).o sdram.o
+COBJS	= $(BOARD).o cmd_sequoia.o sdram.o
 SOBJS	= init.o
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)