GCC4.6: Squash warnings in lattice.c

lattice.c:319:4: warning: format '%x' expects type 'unsigned int', but argument
3 has type 'const char *'
lattice.c:319:4: warning: format '%x' expects type 'unsigned int', but argument
4 has type 'long unsigned int'

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Mike Frysinger <vapier@gentoo.org>