clocksource: exynos_mct: Don't reset the counter during boot and resume

Unfortunately on some exynos systems, resetting the mct counter also
resets the architected timer counter.  This can cause problems if the
architected timer driver has already been initialized because the kernel
will think that the counter has wrapped around, causing a big jump in
printk timestamps and delaying any scheduled clock events until the
counter reaches the value it had before it was reset.

The kernel code makes no assumptions about the initial value of the mct
counter so there is no reason from a software perspective to clear the
counter before starting it.  This also fixes the problems described in
the previous paragraph.

Cc: Olof Johansson <olof@lixom.net>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>