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
1 file changed