igc: Fix TX timestamp support for non-MSI-X platforms

stable inclusion
from stable-v5.10.90
commit b7c9a1427b32723b583da6d44d833e9b246d4a94
bugzilla: 186168 https://gitee.com/openeuler/kernel/issues/I4SHY1

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b7c9a1427b32723b583da6d44d833e9b246d4a94



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[ Upstream commit f85846bb ]

Time synchronization was not properly enabled on non-MSI-X platforms.

Fixes: 2c344ae2 ("igc: Add support for TX timestamping")
Signed-off-by: James McLaughlin <james.mclaughlin@qsc.com>
Reviewed-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Nechama Kraus <nechamax.kraus@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>