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_features.h b/include/arch/aarch32/arch_features.h
index 62a512b..67059f2 100644
--- a/include/arch/aarch32/arch_features.h
+++ b/include/arch/aarch32/arch_features.h
@@ -116,4 +116,22 @@
 	return false;
 }
 
+static inline unsigned int read_feat_pan_id_field(void)
+{
+	return ISOLATE_FIELD(read_id_mmfr3(), ID_MMFR3_PAN);
+}
+
+static inline bool is_feat_pan_supported(void)
+{
+	if (ENABLE_FEAT_PAN == FEAT_STATE_DISABLED) {
+		return false;
+	}
+
+	if (ENABLE_FEAT_PAN == FEAT_STATE_ALWAYS) {
+		return true;
+	}
+
+	return read_feat_pan_id_field() != 0U;
+}
+
 #endif /* ARCH_FEATURES_H */