The IoT slot driver provides a more modular replacement for the mangoh
driver which is part of the legato framework.  The idea is to separate
out the installation of various sensor devices and the IoT card
framework.

The directory has been placed at linux_kernel_modules/iot_slot/ since
mangoh is an existing driver in this folder.

Media Tek's instructions

  - CP2130
  - MT7697q
  - MT7697WiFi

bring up/down the mt6597q driver as legato now does this.

Added two new scripts for copying files to the MangOH Red and for
configuring the MT7697 networking.

inside interrupt handler worker flag is checked before calling the
notify blocked writer fcn.  Inside notify blocked write fcn the
blocked writer flag is unset if writer is no longer blocked.

writer is blocked

MT7697 wifi updated to check and send outstanding tx packets when processing
the interrupt.

available is less than what is required to execute the write.

TODO:  Try moving the rd offset to the interrupt hndlr and update
       MT7697 code to set the interrupt and queue flag when the rd
       offset is updated.  See which method is best......

STA and AP modes

Including the spisvc module in the SDEF makes it easier to get started
with the spiService.

by leaving op mode to STA and updating upmode just before setting
AP SSID.

  - reduced delay check of interrupt
  - fixed order issue in driver Tx
  - removed status register checks in SPI queue read/write

There is now a mangoh_red and a mangoh_green module.  The universal
mangoh module did very little in terms of code sharing so it made
sense to split it into two simpler modules.