powerpc/fsl: Fix spectre_v2 mitigations reporting

powerpc/fsl: Fix spectre_v2 mitigations reporting

Currently for CONFIG_PPC_FSL_BOOK3E the spectre_v2 file is incorrect:

  $ cat /sys/devices/system/cpu/vulnerabilities/spectre_v2
  "Mitigation: Software count cache flush"

Which is wrong. Fix it to report vulnerable for now.

BugLink: https://bugs.launchpad.net/bugs/1822870
Fixes: ee13cb249fab ("powerpc/64s: Add support for software count cache flush")
Cc: stable@vger.kernel.org # v4.19+
BugLink: https://bugs.launchpad.net/bugs/1822870
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit 7d8bad99ba5a22892f0cad6881289fdc3875a930)
Signed-off-by: Manoj Iyer <manoj.iyer@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>