habanalabs: refactoring in goya.c

This patch does some refactoring in goya.c to make code more reusable
between goya code and the goya simulator code (which is not upstreamed).

In addition, the patch removes some dead functions from goya.c which are
not used by the current upstream code

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>