Add qcpas(4), a driver for the Peripheral Authentication Service found on

Add qcpas(4), a driver for the Peripheral Authentication Service found on
Qualcomm SoCs.

The immediate task for this driver is to provide firmware to the auxiliary
cores and to bring them up.  This is accomplished by parsing the ELF files
and providing the data in certain memory regions, and telling qcscm(4) to
check and execute the firmware on the auxiliary cores.

With the cores up we can now talk to the firmware.  The glink-edge subnode
indicates that we can talk to it using the GLINK protocol over shared memory
provided by qcsmem(4).  This interface is essentially a channel multiplexer,
with each channel identified through an ASCII string.

One of those channels connects to a PMIC router, which allows us to talk to
the battery manager service that contains information about the charging and
battery states.

ok drahn@ kettenis@