intel_pmc_ipc: Avoid pending IPC1 command during legacy suspend

During legacy suspend flow, IPC1 commands are being requested
from opregion driver. But the PMC_IPC1 command will timeout as example:

[  281.444600] ipc_debug##: ipc_send_command: cmd=0x201ff,
[  281.444648] wbuf[0]=0x4ea6
[  281.444668] wbuf[1]=0x0
[  281.444674] wbuf[2]=0x0
[  281.444676] wbuf[3]=0x0
[  284.446467] pmc-ipc-plat INT34D2:00: IPC timed out, TS=0x4, CMD=0x200ff

This is because before the opregion driver could send IPC1 commands,
the PMC_IPC irq is already suspended. Which makes the IPC command to
timeout.

Solution: register pmc_ipc irq as IRQF_NO_SUSPEND

Signed-off-by: Ananth Krishna R <ananth.krishna.r@intel.com>
Signed-off-by: Bharath K Veera <bharath.k.veera@intel.com>
Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>