feat(cpufeat): add AArch32 PAN detection support

FEAT_PAN is implemented in AArch32 as well, provide the helper functions
to query the feature availability at runtime.

Change-Id: I375e3eb7b05955ea28a092ba99bb93302af48a0e
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/include/arch/aarch32/arch_helpers.h b/include/arch/aarch32/arch_helpers.h
index 95d056f..a7954cc 100644
--- a/include/arch/aarch32/arch_helpers.h
+++ b/include/arch/aarch32/arch_helpers.h
@@ -217,6 +217,7 @@
  ******************************************************************************/
 DEFINE_COPROCR_READ_FUNC(mpidr, MPIDR)
 DEFINE_COPROCR_READ_FUNC(midr, MIDR)
+DEFINE_COPROCR_READ_FUNC(id_mmfr3, ID_MMFR3)
 DEFINE_COPROCR_READ_FUNC(id_mmfr4, ID_MMFR4)
 DEFINE_COPROCR_READ_FUNC(id_dfr0, ID_DFR0)
 DEFINE_COPROCR_READ_FUNC(id_pfr0, ID_PFR0)