v3d: Clean up vestiges of alpha test lowering.

We had an unnecessary case in our uniforms upload switch statement, since
we no longer advertise the cap.

Fixes: 8ad931808e ("v3d: do not report alpha-test as supported")
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8601>

src/broadcom/compiler/v3d_compiler.h

@@ -280,8 +280,6 @@ enum quniform_contents {
         QUNIFORM_IMAGE_DEPTH,
         QUNIFORM_IMAGE_ARRAY_SIZE,
 
-        QUNIFORM_ALPHA_REF,
-
         QUNIFORM_LINE_WIDTH,
 
         /* The line width sent to hardware. This includes the expanded width
@@ -386,7 +384,6 @@ struct v3d_fs_key {
         bool is_points;
         bool is_lines;
         bool line_smoothing;
-        bool alpha_test;
         bool point_coord_upper_left;
         bool light_twoside;
         bool msaa;
@@ -414,7 +411,6 @@ struct v3d_fs_key {
                 const uint8_t *swizzle;
         } color_fmt[V3D_MAX_DRAW_BUFFERS];
 
-        uint8_t alpha_test_func;
         uint8_t logicop_func;
         uint32_t point_sprite_mask;