android: silence ~550 warnings

Analogous to the autoconf build add the following to the build

   -Wno-unused-parameter
   -Wno-missing-field-initializers

Cc: Chih-Wei Huang <cwhuang@android-x86.org>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>