optee: Add lib entries for sharing OPTEE code across ports

This patch adds code to lib to enable sharing of useful OPTEE code between
board-ports and architectures. The code on lib/optee/optee.c comes from the
TI omap2 port. Eventually the OMAP2 code will be patched to include the
shared code. The intention here is to add more useful OPTEE specific code
as more functionality gets added.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc: Harinarayan Bhatta <harinarayan@ti.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Tom Rini <trini@konsulko.com>
Cc: Kever Yang <kever.yang@rock-chips.com>
Cc: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Cc: Peng Fan <peng.fan@nxp.com>
Tested-by: Peng Fan <peng.fan@nxp.com>
diff --git a/include/tee/optee.h b/include/tee/optee.h
index 9ab0d08..8943afb 100644
--- a/include/tee/optee.h
+++ b/include/tee/optee.h
@@ -10,6 +10,8 @@
 #ifndef	_OPTEE_H
 #define _OPTEE_H
 
+#include <linux/errno.h>
+
 #define OPTEE_MAGIC             0x4554504f
 #define OPTEE_VERSION           1
 #define OPTEE_ARCH_ARM32        0
@@ -27,4 +29,18 @@
 	uint32_t paged_size;
 };
 
+#if defined(CONFIG_OPTEE)
+int optee_verify_image(struct optee_header *hdr, unsigned long tzdram_start,
+		       unsigned long tzdram_len, unsigned long image_len);
+#else
+static inline int optee_verify_image(struct optee_header *hdr,
+				     unsigned long tzdram_start,
+				     unsigned long tzdram_len,
+				     unsigned long image_len)
+{
+	return -EPERM;
+}
+
+#endif
+
 #endif /* _OPTEE_H */