tmgr: Full rework of timers library

Now structure is a bit closer to Linux kernel timers.

See docs for further information.

Signed-off-by: Nikita 'webconn' Maslov <wkernelteam@gmail.com>
tmgr: Fix unnecessary config in kcnf

Remove Mode of Operation config entry.

Signed-off-by: Nikita 'webconn' Maslov <wkernelteam@gmail.com>
tmgr: Fix queue operation and remove tmgr_set_fq()

Now queue works more correct. Also, tmgr_set_fq() functions
removed (you still need to set system timer frequency in menuconfig
(see docs)

Signed-off-by: Nikita 'webconn' Maslov <wkernelteam@gmail.com>