octeontx2-sdpvf: Fix PTP options for SDP interfaces

commit a89caa835e9fd749aeb398d6c965f83a4819a6a5 from
git@git.assembla.com:cavium/WindRiver.linux.git

SDP interfaces do not support hardware PTP timestamping, so only advertise
SW PTP for SDP interfaces.

Signed-off-by: Roy Franz <rfranz@marvell.com>
Change-Id: I09d8af4bd35ae13388f5d162b8feda93cbc5cf44
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/77337


Tested-by: sa_ip-sw-jenkins <sa_ip-sw-jenkins@marvell.com>
Reviewed-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Ruiqiang Hao <Ruiqiang.Hao@windriver.com>