Change IMAGE_TLV_RSA2048 -> IMAGE_TLV_RSA2048_PSS

Clarify the name of the TLV field to more fully describe the signature
type.

Signed-off-by: Marko Kiiskila <marko@runtime.io>
Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/boot/bootutil/src/image_validate.c b/boot/bootutil/src/image_validate.c
index 003620c..c9144cb 100644
--- a/boot/bootutil/src/image_validate.c
+++ b/boot/bootutil/src/image_validate.c
@@ -94,7 +94,7 @@
  * configured for any signature, don't define this macro.
  */
 #if defined(MCUBOOT_SIGN_RSA)
-#    define EXPECTED_SIG_TLV IMAGE_TLV_RSA2048
+#    define EXPECTED_SIG_TLV IMAGE_TLV_RSA2048_PSS
 #    define EXPECTED_SIG_LEN(x) ((x) == 256) /* 2048 bits */
 #    if defined(MCUBOOT_SIGN_EC) || defined(MCUBOOT_SIGN_EC256)
 #        error "Multiple signature types not yet supported"