net: stmmac: SDx55: add pps signal and interrupts support

Add ioctl support to handle and generate pps siganal &
interrupt.Add device nodes for pps interrupts to interact
with user space.

Change-Id: I401326443e69bfd0fb37986004bdc47f41dc57b7
Acked-by: Nagarjuna Chaganti <nchagant@qti.qualcomm.com>
Signed-off-by: Suraj Jaiswal <jsuraj@codeaurora.org>