pan/mdg: Set types for derivatives

Closes #2900

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5014>
diff --git a/src/panfrost/midgard/midgard_derivatives.c b/src/panfrost/midgard/midgard_derivatives.c
index cfb3c08..c9c6c02 100644
--- a/src/panfrost/midgard/midgard_derivatives.c
+++ b/src/panfrost/midgard/midgard_derivatives.c
@@ -102,7 +102,9 @@
                 .type = TAG_TEXTURE_4,
                 .mask = mask_of(nr_components),
                 .dest = nir_dest_index(&instr->dest.dest),
+                .dest_type = nir_type_float32,
                 .src = { nir_src_index(ctx, &instr->src[0].src), ~0, ~0, ~0 },
+                .src_types = { nir_type_float32, nir_type_float32 },
                 .texture = {
                         .op = mir_derivative_op(instr->op),
                         .format = MALI_TEX_2D,