.gitignore: ignore u-boot.elf and tools/relocate-rela

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/.gitignore b/.gitignore
index 3b14c25..97f7db0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -29,6 +29,7 @@
 /SPL
 /System.map
 /u-boot
+/u-boot.elf
 /u-boot.hex
 /u-boot.imx
 /u-boot-with-spl.imx