FwImage: update firmware to mxm6x17408

Updated firmware:
SDIO-UART W8987 Firmware version 16.92.21.p99
SDIO_UART IW612 Firmware version 18.99.2.p19.6
SDIO-UART W9098 Firmware version 17.92.1.p136.128
PCIE-UART W9098 Firmware version 17.92.1.p136.129
SDIO-UART W8801 Firmware version 14.92.36.p182

Unchanged firmware:
PCIE-UART W8997 Firmware version 16.92.21.p84.4
SDIO-UART W8997 Firmware version 16.92.21.p84.4
SDIO-UART IW416 Firmware version 16.92.21.p84.3

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>

nxp/mfguart/README.txt

@@ -0,0 +1,65 @@
+The helper_uart is a UART download helper for boosting firmware UART
+download speed.
+
+Without such a helper, the normal firmware download baudrate is fixed
+to 115200bps by bootrom code. When using the helper, the bootrom first
+download the helper itself at the fixed baudrate. Then the helper
+runs and changes the UART baudrate to a higher speed, say 3Mbps. And
+finally the firmware is downloaded at this high speed to save the
+total download time.
+
+The helper is very small, less than 3KB. So it can be downloaded very
+fast even at 115200bps baudrate. Time saved using higher baudrate for
+downloading firmware easily compensate for the time in downloading
+the small helper itself. 
+
+Uart download related files:
+       |-fw_loader_arm
+       |-fw_loader_linux
+       |-fw_loader_win.exe
+       |-helper_uart_115200.bin
+       |-helper_uart_230400.bin
+       |-helper_uart_921600.bin
+       |-helper_uart_2000000.bin
+       |-helper_uart_3000000.bin
+       |-helper_uart_3250000.bin
+
+Eg: fw_loader.exe com1 115200 0 helper_uart_3000000.bin
+
+How to download the FW image:
+We use a marvell proprietary protocol to download the FW image.
+Please refer to UART_HELPER.txt for more details on the protocol.
+
+We use the new helper protocol to download both the helper and the FW image.
+
+Once the FW is downloaded on the chip, it automatically starts running
+from its entry point. 
+
+There are different fw_loader executables available depending on the 
+Platform on which it is to be run.
+
+Boot ROM code does not enable UART HW flow control. This means that while 
+downloading the helper, Flow Control should be disabled. Once the helper 
+is downloaded, Flow Control should be set to 1, to download the FW.
+
+<Format: fw_loader_win.exe ComPort BaudRate FlowControl FileName>
+
+e.g.
+Windows:
+Download Helper:
+     fw_loader_win.exe com1 115200 0 helper_uart_3000000.bin
+Download FW image at specified BaudRate:
+     fw_loader_win.exe com1 3000000 1 firmware.image
+
+Linux:
+Download Helper:
+     ./fw_loader_linux /dev/ttyUSB# 115200 0 helper_uart_3000000.bin
+Download FW image at specified BaudRate:
+     ./fw_loader_linux /dev/ttyUSB# 3000000 1 firmware.image
+
+Saar:
+Download Helper:
+     ./fw_loader_arm /dev/ttyUSB# 115200 0 helper_uart_3000000.bin
+Download FW image at specified BaudRate:
+     ./fw_loader_arm /dev/ttyUSB# 3000000 1 firmware.image
+