uart qmsi: Fix definition of device_pm_ops

The macro defining the device_pm_ops structs is located inside an
ifdef for CONFIG_UART_QMSI_0, so when the UART_0 is disabled at build
time, but UART_1 is still used, it references a struct not defined.

Fix it by placing the DEFINE_DEVICE_PM_OPS line outside the ifdef block.

Change-Id: I7dafda162741201ee47b5b480c07ec8c1f373d64
Signed-off-by: Iván Briano <ivan.briano@intel.com>