qemu 7.2 no longer carries libslirp in-tree, and so
it has to be provided externally.
(From OE-Core rev: a4409583e0f8187b0c0cbf92fbddeffef12fd8f5)
Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>