Some code cleanup for GCC 4.x

CHANGELOG

board/at91rm9200dk/at45.c

board/at91rm9200dk/flash.c

board/cmc_pu2/load_sernum_ethaddr.c

board/delta/nand.c

board/lart/flash.c

board/lpd7a40x/flash.c

board/netstar/crcek

board/netstar/eeprom

board/netstar/flash.c

board/netstar/nand.c

board/shannon/flash.c

common/env_nand.c

cpu/arm920t/at91rm9200/i2c.c

drivers/dataflash.c

drivers/lan91c96.c

drivers/lan91c96.h

drivers/nand/nand_base.c

drivers/smc91111.c

drivers/smc91111.h