kernel: package QRTR support

kernel: package QRTR support

QRTR is Qualcomm IPC router protocol and ath11k requires it for both
AHB and PCI support, so package it as a kernel module so it can be
added as a dependency to the ath11k module.

Only kernel 5.15 is currently supported due to various things missing in
5.10 whose backporting is out of scope for this patch.

SMD, TUN and MHI variants are packaged.

SMD variant depends on the ipq807x
target as it has dependency on the RPMSG drivers which are Qualcomm
and SoC specific anyway.

Signed-off-by: Robert Marko <robimarko@gmail.com>