etnaviv: set LOGIC_OP_UNK24 for MSAA rendering on SMALL_MSAA GPUs

Fixes MSAA corruptions on GC3000. 0x4 seems to be enough to fix the
misrendering, but blob seems to always emit 0x5.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19066>

src/gallium/drivers/etnaviv/etnaviv_state.c

@@ -361,6 +361,8 @@ etna_set_framebuffer_state(struct pipe_context *pctx,
       cs->RA_CENTROID_TABLE[9] = 0x886688a2;
       cs->RA_CENTROID_TABLE[10] = 0x888866aa;
       cs->RA_CENTROID_TABLE[11] = 0x668888a6;
+      if (VIV_FEATURE(screen, chipMinorFeatures4, SMALL_MSAA))
+         pe_logic_op |= VIVS_PE_LOGIC_OP_UNK24(0x5);
       break;
    }