powerpc/85xx: Fix compile errors if CONFIG_SYS_{B,Q}MAN_MEM_PHYS aren't set

Add ifdef protection in LAW & TLB code to handle the case in which
CONFIG_SYS_BMAN_MEM_PHYS or CONFIG_SYS_QMAN_MEM_PHYS arent defined for a
build.

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