build-setup: switch default target to qemuarm

There is no target named just 'qemu', but 'qemu<arch>'.
Since most BMC chips are arm32, default to 'qemuarm'.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ib21bb29274c8eebf91d37b4dd0e952bac1d8e0e8
diff --git a/build-setup.sh b/build-setup.sh
index 575b3a1..234fd10 100755
--- a/build-setup.sh
+++ b/build-setup.sh
@@ -42,7 +42,7 @@
 #                     evb-ast2500|palmetto|qemu|qemux86-64
 #                     romulus|s2600wf|witherspoon|zaius|tiogapass|gsj|mihawk
 #                     witherspoon-tacoma|rainier
-#                     Default: "qemu"
+#                     Default: "qemuarm"
 #  no_tar             Set to true if you do not want the debug tar built
 #                     Default: "false"
 #  nice_priority      Set nice priotity for bitbake command.
@@ -90,7 +90,7 @@
 build_dir=${build_dir:-${WORKSPACE}/build}
 distro=${distro:-ubuntu}
 img_tag=${img_tag:-latest}
-target=${target:-qemu}
+target=${target:-qemuarm}
 no_tar=${no_tar:-false}
 nice_priority=${nice_priority:-}