MDEV-32935: Remove unneeded CMAKE_SYSTEM_PROCESSOR parameter from Debian

There is no need for CMAKE_SYSTEM_PROCESSOR parameter in Debian
build as dh_auto_configure should handle things better and
more reliable

debian/rules

@@ -89,7 +89,6 @@ endif
 	    -DCOMPILATION_COMMENT="mariadb.org binary distribution" \
 	    -DMYSQL_SERVER_SUFFIX="-$(DEB_VERSION_REVISION)" \
 	    -DSYSTEM_TYPE="debian-$(DEB_HOST_GNU_SYSTEM)" \
-	    -DCMAKE_SYSTEM_PROCESSOR=$(DEB_HOST_ARCH) \
 	    -DBUILD_CONFIG=mysql_release \
 	    -DPLUGIN_TOKUDB=NO \
 	    -DPLUGIN_CASSANDRA=NO \