Remove temporary ppc64 workarounds

[grisu48]

In #646 we introduced the workaround to skip the boottime test on ppc64le due to openQA worker problems. This workaround should be removed once we have the workers back.

[grisu48]

More PRs to be reverted:

• Temporarily increase timeouts #650
• Increase distribution image timeout on ppc64le #652
• Add startup delay of 1min to git healthcheck #657
• Skip glob repo on ppc64 #658

[mgrossu]

More PRs to be reverted:

• Increase timeouts postgres #655

[grisu48]

FYI - We could move most BCI tests back to actual PowerPC workers, but still need emulated workers for SLES16, so this is still WIP.