Revert "net: stmmac: re-init rx buffers when mac resume back"

This reverts commit 9c63faaa, which
introduces a suspend/resume regression on Jetson TX2 boards that can be
reproduced every time. Given that the issue that this was supposed to
fix only occurs very sporadically the safest course of action is to
revert before v5.12 and then we can have another go at fixing the more
rare issue in the next release (and perhaps backport it if necessary).

The root cause of the observed problem seems to be that when the system
is suspended, some packets are still in transit. When the descriptors
for these buffers are cleared on resume, the descriptors become invalid
and cause a fatal bus error.

Link: https://lore.kernel.org/r/708edb92-a5df-ecc4-3126-5ab36707e275@nvidia.com/


Reported-by: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>