trace: Use correct trace class for power management changes

trace: Use correct trace class for power management changes

Previous to this patch we would see in the trace file:

CPU28  1753503175371 (+    8496)  unknown (0x0000000000801002)  [ 0x00000004 0x4158a498 0x000003a1 0x000027e6 0x00000000 0x00000000 0x00000000 ]
CPU28  1753505321239 (+ 2145868)  unknown (0x0000000000801003)  [ 0x00000004 0x4166dca7 0x000000fa 0x00000000 0x00000000 0x00000000 0x00000000 ]
CPU28  1753505343756 (+   22517)  unknown (0x0000000000801002)  [ 0x00000004 0x41670fe5 0x00001284 0x00003766 0x00000000 0x00000000 0x00000000 ]
CPU28  1753521413711 (+16069955)  unknown (0x0000000000801003)  [ 0x00000004 0x41d1e02c 0x000000ab 0x00000000 0x00000000 0x00000000 0x00000000 ]

instead of:
CPU28  1753503175371 (+    8496)  cpu_idle_entry  [ C0 -> C4, acpi_pm_tick = 1096328344, expected = 929us, predicted = 10214us ]
CPU28  1753505321239 (+ 2145868)  cpu_idle_exit   [ C4 -> C0, acpi_pm_tick = 1097260199, irq = 250 0 0 0 ]
CPU28  1753505343756 (+   22517)  cpu_idle_entry  [ C0 -> C4, acpi_pm_tick = 1097273317, expected = 4740us, predicted = 14182us ]
CPU28  1753521413711 (+16069955)  cpu_idle_exit   [ C4 -> C0, acpi_pm_tick = 1104273452, irq = 171 0 0 0 ]

The patch that added the cpu_idle_[entry|exit] was using the
TRC_HW_IRQ class (0x00802000) instead of TRC_HW_PM (0x00801000)
as a base.

Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>