board: sl28: add OP-TEE Trusted OS support (bl32)

Add support to load the OP-TEE Trusted OS by the SPL.

Signed-off-by: Michael Walle <michael@walle.cc>
diff --git a/board/kontron/sl28/Kconfig b/board/kontron/sl28/Kconfig
index aba49fc..4078ef1 100644
--- a/board/kontron/sl28/Kconfig
+++ b/board/kontron/sl28/Kconfig
@@ -25,4 +25,27 @@
 	  Enable this to load a BL31 image by the SPL. You have to
 	  provde a bl31.bin in u-boot's root directory.
 
+if SL28_SPL_LOADS_ATF_BL31
+
+config SL28_BL31_ENTRY_ADDR
+	hex "Entry point of the BL31 image"
+	default 0xfbe00000
+
+endif
+
+config SL28_SPL_LOADS_OPTEE_BL32
+	bool "SPL loads OP-TEE Trusted OS as BL32"
+	depends on SL28_SPL_LOADS_ATF_BL31
+	help
+	  Enable this to load a BL32 image by the SPL. You have to
+	  provde a tee.bin in u-boot's root directory.
+
+if SL28_SPL_LOADS_OPTEE_BL32
+
+config SL28_BL32_ENTRY_ADDR
+	hex "Entry point of the BL32 image"
+	default 0xfc000000
+
+endif
+
 endif