qemu: Remove need for qemuDomainParseIOThreadAlias

qemu: Remove need for qemuDomainParseIOThreadAlias

Rather than have a separate routine to parse the alias of an iothread
returned from qemu in order to get the iothread_id value, parse the alias
when returning and just return the iothread_id in qemuMonitorIOThreadInfoPtr

This set of patches removes the function, changes the "char *name" to
"unsigned int" and handles all the fallout.