The original BSP qemuarm has been renamed to qemuarmv5. Update the machine
overrides accordingly to avoid not generating dtb.
(From OE-Core rev: a1ac097686daf0769e7ff94ff2c8795e1e8ae790)
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>