coregl_fastpath: Fix issue occurs in vertex array Enable/Disabe

coregl_fastpath: Fix issue occurs in vertex array Enable/Disabe

Whether an vertex array is bounded or not, value of
state gl_vertex_array_enabled should be always
updated once fastpath_glEnableVertexAttribArray or
fastpath_glDisableVertexAttribArray is called, if not,
it will cause state confusion

Once an vertex array is unbounded or an new vertex
array is bounded, value of state gl_vertex_array_enabled
should be cleared

Signed-off-by: Zhaowei Yuan <zhaowei.yuan@samsung.com>
Change-Id: I7d686cc603dfb74e305c64687eaea36be6f1aea1