glsl: don't run intrastage array validation when the interface type is not an array

glsl: don't run intrastage array validation when the interface type is not an array

We validate that the interface block array type's definition matches.
However, previously, the function could be called if an non-array
interface block has different type definitions -for example, when the
precision qualifier differs in a GLSL ES shader, we would create two
different types-, and it would return invalid as both definitions are
non-arrays.

We fix this by specifying that at least one definition should be an
array to call the validation.

Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>