The Physical Core events of the 24x7 PMU can be monitored across various
domains (physical core, vcpu home core, vcpu home node etc). For each of
these core events, we currently create multiple events in sysfs, one for
each domain the event can be monitored in. These events are distinguished
by their suffixes like __PHYS_CORE, __VCPU_HOME_CORE etc.

Rather than creating multiple such entries, we could let the user specify
make 'domain' index a required parameter and let the user specify a value
for it (like they currently specify the core index).

	$ cat /sys/bus/event_source/devices/hv_24x7/events/HPM_CCYC
	domain=?,offset=0x98,core=?,lpar=0x0

	$ perf stat -C 0 -e hv_24x7/HPM_CCYC,domain=2,core=1/ true

(the 'domain=?' and 'core=?' in sysfs tell perf tool to enforce them as
required parameters).

This simplifies the interface and allows users to identify events by the
name specified in the catalog (User can determine the domain index by
referring to '/sys/bus/event_source/devices/hv_24x7/interface/domains').

Eliminating the event suffix eliminates several functions and simplifies
code.

Note that Physical Chip events can only be monitored in the chip domain
so those events have the domain set to 1 (rather than =?) and users don't
need to specify the domain index for the Chip events.

	$ cat /sys/bus/event_source/devices/hv_24x7/events/PM_XLINK_CYCLES
	domain=1,offset=0x230,chip=?,lpar=0x0

	$ perf stat -C 0 -e hv_24x7/PM_XLINK_CYCLES,chip=1/ true
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>