oeqa/core/target/qemu.py: display contents of dumped files
During do_testimage, if the target is not started within a certain
timeout, TEST_QEMUBOOT_TIMEOUT, host data is dumped to files for
each command in
${TMPDIR}/log/runtime-hostdump/<datetime>_qemu/host_<seq>_<command>.
Display the first 20 lines of top output and the last 20 lines of
bootlog to standard output for more context for the target not being
started up.
Signed-off-by: Sakib Sajal <sakib.sajal@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
