Revert "mantle/kola/tests: disable RAID tests on aarch64/ppc64le"

As of coreos/butane#278 in Butane 0.14.0, Butane
RAID templates now create reserved partitions on aarch64 and ppc64le to
keep partition numbers aligned across platforms.

Fixes coreos/fedora-coreos-tracker#855.

This reverts commit 46af3f4.

mantle/kola/tests/misc/boot-mirror.go

@@ -60,10 +60,8 @@ func init() {
 		ClusterSize: 0,
 		Name:        `coreos.boot-mirror`,
 		Platforms:   []string{"qemu-unpriv"},
-		// aarch64 and ppc64le have buggy partition layouts
-		// https://github.com/coreos/fedora-coreos-tracker/issues/855#issuecomment-896387343
 		// Can't mirror boot disk on s390x
-		ExcludeArchitectures: []string{"aarch64", "ppc64le", "s390x"},
+		ExcludeArchitectures: []string{"s390x"},
 		// skipping this test on UEFI until https://github.com/coreos/coreos-assembler/issues/2039
 		// gets resolved.
 		ExcludeFirmwares: []string{"uefi"},
@@ -76,11 +74,9 @@ func init() {
 		ClusterSize: 0,
 		Name:        `coreos.boot-mirror.luks`,
 		Platforms:   []string{"qemu-unpriv"},
-		// aarch64 and ppc64le have buggy partition layouts
-		// https://github.com/coreos/fedora-coreos-tracker/issues/855#issuecomment-896387343
 		// Can't mirror boot disk on s390x, and qemu s390x doesn't
 		// support TPM
-		ExcludeArchitectures: []string{"aarch64", "ppc64le", "s390x"},
+		ExcludeArchitectures: []string{"s390x"},
 		// skipping this test on UEFI until https://github.com/coreos/coreos-assembler/issues/2039
 		// gets resolved.
 		ExcludeFirmwares: []string{"uefi"},