[app][hwcrypto] Explicitly include arch-specific headers.

Change-Id: I3da1434e13b44c02e7facf9e8213c047a6d32012
diff --git a/app/hwcrypto/rules.mk b/app/hwcrypto/rules.mk
index a4a2178..2d07696 100644
--- a/app/hwcrypto/rules.mk
+++ b/app/hwcrypto/rules.mk
@@ -31,6 +31,9 @@
 MODULE_DEFINES := \
 	TLOG_LVL_DEFAULT=2 \
 
+MODULE_INCLUDES := \
+	$(LOCAL_DIR)/../../platform/imx/soc/$(PLATFORM_SOC)/include
+
 MODULE_DEPS := \
 	app/trusty \
 	lib/libc-trusty \