net/mlx5e: Remove the false indication of software timestamping support

net/mlx5e: Remove the false indication of software timestamping support

BugLink: https://bugs.launchpad.net/bugs/1837257
[ Upstream commit 4765420439e758bfa4808392d18b0a4cb6f06065 ]

mlx5 driver falsely advertises support of software timestamping.
Fix it by removing the false indication.

Fixes: ef9814deafd0 ("net/mlx5e: Add HW timestamping (TS) support")
Signed-off-by: Alaa Hleihel <alaa@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>