v3dv: Call nir_lower_io for push constants

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6766>
diff --git a/src/broadcom/vulkan/v3dv_pipeline.c b/src/broadcom/vulkan/v3dv_pipeline.c
index 0924550..4751fda 100644
--- a/src/broadcom/vulkan/v3dv_pipeline.c
+++ b/src/broadcom/vulkan/v3dv_pipeline.c
@@ -367,6 +367,10 @@
    }
 
    NIR_PASS_V(nir, nir_lower_explicit_io,
+              nir_var_mem_push_const,
+              nir_address_format_32bit_offset);
+
+   NIR_PASS_V(nir, nir_lower_explicit_io,
               nir_var_mem_ubo | nir_var_mem_ssbo,
               nir_address_format_32bit_index_offset);