powerpc/85xx: Fix compile warnings in mpc85xx_mds.c

arch/powerpc/platforms/85xx/mpc85xx_mds.c: In function 'board_fixups':
arch/powerpc/platforms/85xx/mpc85xx_mds.c:244: warning: format '%x' expects type 'unsigned int', but argument 4 has type 'resource_size_t'
arch/powerpc/platforms/85xx/mpc85xx_mds.c:250: warning: format '%x' expects type 'unsigned int', but argument 4 has type 'resource_size_t'

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>