feat(lib/psa): add read_measurement API

This API is added for testing purposes. It makes possible to write test
cases that read measurements back after extending them, and compare
them to expected results.

Change-Id: Iec447d972fdd54a56ab933a065476e0f4d35a6fc
Signed-off-by: Mate Toth-Pal <mate.toth-pal@arm.com>
diff --git a/lib/psa/measured_boot_private.h b/lib/psa/measured_boot_private.h
index 649c3f6..80d2c19 100644
--- a/lib/psa/measured_boot_private.h
+++ b/lib/psa/measured_boot_private.h
@@ -11,8 +11,24 @@
 #include <stdint.h>
 
 /* Measured boot message types that distinguish its services */
+#define RSS_MEASURED_BOOT_READ		1001U
 #define RSS_MEASURED_BOOT_EXTEND	1002U
 
+struct measured_boot_read_iovec_in_t {
+    uint8_t index;
+    uint8_t sw_type_size;
+    uint8_t version_size;
+};
+
+struct measured_boot_read_iovec_out_t {
+    uint8_t  is_locked;
+    uint32_t measurement_algo;
+    uint8_t  sw_type[SW_TYPE_MAX_SIZE];
+    uint8_t  sw_type_len;
+    uint8_t  version[VERSION_MAX_SIZE];
+    uint8_t  version_len;
+};
+
 struct measured_boot_extend_iovec_t {
 	uint8_t  index;
 	uint8_t  lock_measurement;