Revert "MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET"

This reverts commit 3f4579252aa166641861a64f1c2883365ca126c2. It is
invalid because the macros CAC_ADDR and UNCAC_ADDR have a kernel
virtual address as an argument and also returns a kernel virtual
address. Using and physical address PHYS_OFFSET is blatantly wrong
for a macro common to multiple platforms.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Acked-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Florian Fainelli <florian@openwrt.org>
Patchwork: https://patchwork.linux-mips.org/patch/5528/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>