clocksource: move the NSEC_PER_SEC constant to common header ...

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

include/linux/time.h: remove dead code ...

include/linux/time.h contains several unused functions derived from U-Boot
code. Since this is a file under include/linux/ it should contain only code
from the kernel, so remove all this.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Initial revision