ptp: Reorganize ptp_kvm.c to make it arch-independent

mainline inclusion
from mainline-v5.13-rc1
commit a8cf291b
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8DWT1
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a8cf291bdac5d415eadb55e79df1fca8c3f0dfef



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Currently, the ptp_kvm module contains a lot of x86-specific code.
Let's move this code into a new arch-specific file in the same directory,
and rename the arch-independent file to ptp_kvm_common.c.

Acked-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201209060932.212364-4-jianyong.wu@arm.com


Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
Signed-off-by: Dongxu Sun <sundongxu3@huawei.com>