【MT9669】Kernel传值给PM51

在MT9669里，为了动态配置PM.bin里面的PM Uart串口波特率及唤醒指令，故需从Kernel里面将参数传给PM.bin，从代码看是Mailbox DRAM数据共享方式，其中Kernel部分（kernel/fusion/mstar2）：

Add PMUart baudrate and wakeup command set/get kernel interface implement
Now baudrate parameter just support 2400, 4800, 9600, 14400, 19200, 38400, 57600, 115200, etc.
relate node:
  /sys/devices/virtual/pm/pm/PM_UART_BaudRate
  /sys/devices/virtual/pm/pm/PM_UART_WakeUp_Cmd
     

diff --git a/fusion/mstar2/drv/pm/mdrv_pm.c b/fusion/mstar2/drv/pm/mdrv_pm.c
index 26b7741..ad540b0 100755
--- a/fusion/mstar2/drv/pm/mdrv_pm.c
+++ b/fusion/mstar2/drv/pm/mdrv_pm.c
@@ -118,6 +118,7 @@
 #define PM_OFFSET_IR_VER        (0x0150)
 #define PM_OFFSET_IR_NORMAL