image_types.bbclass: use per-image dirs for extX.gz images generation
Currently image_types.bbclass uses deploy/images/${MACHINE}tpm.gz dir for
temporary files when generating extX.gz images. This can lead to races
and strange errors during image generation. To overcome this use
deploy/images/${MACHINE}tpm.gz-${PN} dir for temporary files.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>