Revert "[RFC PATCH 1/6] ARM, TCM: initialize TCM in paging_init(), instead of setup_arch()"

This reverts commit 14d7a94bdbf27737eb80984401d5a50f1ad5030d.
Revert "[PATCH] process: change from __backtrace to dump_stack in show_regs"

This reverts commit 486956f6fc9003678f49eecf95928055db7fd9d4.
Revert "Disintegrate asm/system.h for ARM"

This reverts commit f681e44374770b396068b4ddcf1f2d673e601145.