v3dv: setup texture shader state correctly for multisampled images

Fixes multisampled cases in:
dEQP-VK.pipeline.multisample.sampled_image.*

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6766>
diff --git a/src/broadcom/vulkan/v3dv_image.c b/src/broadcom/vulkan/v3dv_image.c
index fb2da0d..801d859 100644
--- a/src/broadcom/vulkan/v3dv_image.c
+++ b/src/broadcom/vulkan/v3dv_image.c
@@ -451,7 +451,10 @@
    assert(image_view->image);
    const struct v3dv_image *image = image_view->image;
 
-   int msaa_scale = 1; /* FIXME: hardcoded. Revisit when msaa get supported */
+   assert(image->samples == VK_SAMPLE_COUNT_1_BIT ||
+          image->samples == VK_SAMPLE_COUNT_4_BIT);
+   const uint32_t msaa_scale = image->samples == VK_SAMPLE_COUNT_1_BIT ? 1 : 2;
+
    v3dv_pack(image_view->texture_shader_state[index], TEXTURE_SHADER_STATE, tex) {
 
       tex.level_0_is_strictly_uif =