etnaviv: explicitly set nir_variable_mode

No functional changes - fixes the following assert:
  nir_lower_io_impl: Assertion `!(modes & ~supported_modes)' failed.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5997>
diff --git a/src/gallium/drivers/etnaviv/etnaviv_compiler_nir.c b/src/gallium/drivers/etnaviv/etnaviv_compiler_nir.c
index 44e6c5e..ebaeb7b 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_compiler_nir.c
+++ b/src/gallium/drivers/etnaviv/etnaviv_compiler_nir.c
@@ -1088,7 +1088,7 @@
       assert(sf->num_reg == count);
    }
 
-   NIR_PASS_V(s, nir_lower_io, ~nir_var_shader_out, etna_glsl_type_size,
+   NIR_PASS_V(s, nir_lower_io, nir_var_shader_in | nir_var_uniform, etna_glsl_type_size,
             (nir_lower_io_options)0);
 
    NIR_PASS_V(s, nir_lower_regs_to_ssa);