The /dev/rtc device major value may change depending on the
architecture, and kernel release. To ensure the test rtc is working
all the time, we no longer belong on hard coded major value but peek
it from /dev/rtc itself.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>