image: Rename fit_image_check_hashes() to fit_image_verify()

This is the main entry point to the FIT image verification code. We will
be using it to handle image verification with signatures, so rename the
function.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/common/cmd_fpga.c b/common/cmd_fpga.c
index 1834246..1341604 100644
--- a/common/cmd_fpga.c
+++ b/common/cmd_fpga.c
@@ -306,7 +306,7 @@
 				}
 
 				/* verify integrity */
-				if (!fit_image_check_hashes (fit_hdr, noffset)) {
+				if (!fit_image_verify(fit_hdr, noffset)) {
 					puts ("Bad Data Hash\n");
 					return 1;
 				}