[arm32/Linux] Remove workaround to prevent arm package restore

[gkhanna79]

In dotnet/corefx#15518, we restore packages for x64 (instead of arm) since Arm host packages are not yet available (CoreFX has a cyclic dependency on upstack repo for this).

Once Core-Setup publishes packages for Host for Linux Arm32, dotnet/corefx#15518 should be reverted.

CC @weshaggard @ericstj @hqueue @jyoungyun @hseok-oh

[hqueue]

@gkhanna79 I think we can close this issue, because PR dotnet/corefx#16139 (merged) reverted workaround for arm and add workaround for armel.