linux-yocto: Update dtb path for qemuarmv5

linux-yocto: Update dtb path for qemuarmv5

In Linux kernel versions 6.5 and later, device tree files have been
moved under a vendor directory.  The qemuarmv5 one is now located in
"arm".  Add this to get it working again (which was already done for the
dev kernel in commit 42d5e8ef12934db65c35c1c5f0cabb5c21dbea43).

Once all kernels <v6.5 are removed, this line should probably be
relocated to the qemuarmv5 config file.

Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>