Move PIT driver code to 'drivers/clocsource' and accomodate it by
adjusting Kconfig variables. Rename the file to 'timer-atmel-pit.c' to
re-align the driver with code in Linux kernel.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>