[SRU][X/aws][PATCH 0/1] aws: revert change to support instance types > 255 cpu cores

[Andrea Righi]

BugLink: https://bugs.launchpad.net/bugs/1913739

[Impact]

The following commit was required to properly detect the right amount of
cores in large instance types (with > 255 cpus):

 561ef22a7d396289a1c5a1d18057ccdf9bb59826 "iommu/vt-d: Gracefully handle DMAR units with no supported address widths"

However, this patch seems to work correctly only with kernels > 4.4.
Considering the imminent EOL for this kernel it probably makes sense to
drop this patch for now, to prevent potential regressions.

[Test case]

Tests performed in the AWS cloud, the test case simply consists of
checking the amount of available cpus (running `nproc`).

[Fix]

Revert commit 561ef22a7d396289a1c5a1d18057ccdf9bb59826.

[Regression potential]

This change reverts a previously applied fix (that doesn't actually fix
the problem), so the only downside is simply that not all the available
cores will be detected on the large instance types (basically we are
simply reverting to an old behavior).