include: Remove @defgroup directives from waffle_enum's doxygen
include: Remove @defgroup directives from waffle_enum's doxygen

The @defgroup directives never worked here. Future commits will document
these enums in the doxygen for the function that uses them.

Signed-off-by: Chad Versace <a557f7f75bf28dc19ac99107f5cc7cd6b3fbdb1a@linux.intel.com>

fjhenigman/waffle,chadversary/waffle,waffle-gl/waffle,waffle-gl/waffle,evelikov/waffle,janesma/waffle,dcbaker/waffle,dcbaker/waffle,yinquan529/waffle-gl-waffle,chadversary/waffle,janesma/waffle,evelikov/waffle,fjhenigman/waffle,fjhenigman/waffle,dcbaker/waffle,chadversary/waffle,maurossi/waffle,maurossi/waffle,waffle-gl/waffle,yinquan529/waffle-gl-waffle,waffle-gl/waffle,yinquan529/waffle-gl-waffle,evelikov/waffle,janesma/waffle,maurossi/waffle