Revises the relationships between several configuration options
to support a tickless kernel capabilty. Specifically:
1) SYS_CLOCK_TICKS_PER_SEC is now always defined, so that it can
be referenced by TICKLESS_KERNEL. However, SYS_CLOCK_TICKS_PER_SEC
is forced to 0 when there is no timer interrupt support.
2) NUM_TIMER_PACKETS is now forced to 0 in a microkernel system
when TICKLESS_KERNEL is enabled.
3) TIMESLICING is now disabled when TICKLESS_KERNEL is enabled.
Change-Id: Ie8bf58e7828069afe68ae9451ffbf9bc220ea35f
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>