travis: Exclude omap from the arm926ejs job

We build the platform here that matches with "omap" in its own job,
don't need to have it here as well.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/.travis.yml b/.travis.yml
index 49a7fa9..834502f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -166,7 +166,7 @@
     - name: "buildman arm926ejs (non-NXP,siemens,atmel,kirkwood,spear)"
       env:
         - JOB="arm926ejs"
-          BUILDMAN="arm926ejs -x freescale,siemens,atmel,kirkwood,spear"
+          BUILDMAN="arm926ejs -x freescale,siemens,atmel,kirkwood,spear,omap"
     - name: "buildman atmel"
       env:
         - BUILDMAN="atmel"