Blackfin: fix if() logic in bootrom evt1 check

A missing set of parenthesis caused the silicon revision to apply only to
the BF533 and not the BF531/BF532 variants.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/include/asm-blackfin/blackfin-config-pre.h b/include/asm-blackfin/blackfin-config-pre.h
index a3db362..44f9c2f 100644
--- a/include/asm-blackfin/blackfin-config-pre.h
+++ b/include/asm-blackfin/blackfin-config-pre.h
@@ -55,7 +55,7 @@
 #endif
 
 /* Most bootroms allow for EVT1 redirection */
-#if (defined(__ADSPBF531__) || defined(__ADSPBF532__) || defined(__ADSPBF533__) \
+#if ((defined(__ADSPBF531__) || defined(__ADSPBF532__) || defined(__ADSPBF533__)) \
      && __SILICON_REVISION__ < 3) || defined(__ADSPBF561__)
 # undef CONFIG_BFIN_BOOTROM_USES_EVT1
 #else