u-boot quantenna-sdk-v37.4.8.62 minor tweaks

minor tweaks to the quantenna-sdk-v37.4.8.62 import, updated the
HOW.GFIBER.quantenna.sdk.unpack instructions and removed
quantenna/common/doxygen

Change-Id: I224e3880ad670d3387d6d44c7c888674691c565e
74 files changed