Update references to trusty-specific libc headers

Trusty-specific libc headers have moved to trusty/*. Updates references
to these headers with the new path.

Test: build.py imx7d
Bug: 169448829
Change-Id: Ic4b66c20cc9039b7e8ca49d08e099904efe9899b
diff --git a/app/hwcrypto/caam.c b/app/hwcrypto/caam.c
index 0d6f908..2db6173 100644
--- a/app/hwcrypto/caam.c
+++ b/app/hwcrypto/caam.c
@@ -37,6 +37,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
+#include <trusty/sys/mman.h>
 #include <uapi/err.h>
 
 #include <imx-regs.h>