meta/classes/testimage.bbclass: Only validate IMAGE_FSTYPES when is QEMU
When use simpleremote target the flash/boot process is executed
manually, the IMAGE_FSTYPES validation is only needed when execute
testimage against qemu.
The supported_fstypes comes from oeqa.core.target.qemu module.
(From OE-Core rev:
e7dc5963adbacc091fe8943119262166977623ad)
Signed-off-by: Aníbal Limón <anibal.limon@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
