arch/*: Update atomic functions, style fixes

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>
build: Switch to CMake

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>
kernel/devices: Add uart8250 driver

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>
arch/x86: Dump stack trace at fatal errors

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>