msm: emac: export sysfs nodes for RTC control

Add several sysfs nodes for support of userspace
show/change of PTP timing.

Change-Id: Ibbc8e6a88d8a0c3be89de9ff178e1c42a2b1f59f
Acked-by: Jie Luo <jluo@qti.qualcomm.com>
Signed-off-by: Gilad Avidov <gavidov@codeaurora.org>