DB64460: Fix GCC 4.6 build warnings

Fix:
db64460.c: In function 'debug_led':
db64460.c:413:6: warning: variable 'dummy' set but not used [-Wunused-but-set-variable]
mv_eth.c: In function 'mv64460_eth_real_open':
mv_eth.c:423:6: warning: variable 'port_status' set but not used [-Wunused-but-set-variable]
mv_eth.c: In function 'mv64460_eth_stop':
mv_eth.c:641:15: warning: variable 'port_num' set but not used [-Wunused-but-set-variable]
mv_eth.c: In function 'mv64460_eth_xmit':
mv_eth.c:717:15: warning: variable 'port_num' set but not used [-Wunused-but-set-variable]
mv_eth.c: In function 'mv64460_eth_receive':
mv_eth.c:802:15: warning: variable 'port_num' set but not used [-Wunused-but-set-variable]
mv_eth.c: In function 'mv64460_eth_get_stats':
mv_eth.c:901:15: warning: variable 'port_num' set but not used [-Wunused-but-set-variable]
mv_eth.c: In function 'mv64460_eth_update_stat':
mv_eth.c:929:24: warning: variable 'dummy' set but not used [-Wunused-but-set-variable]
mv_eth.c:928:15: warning: variable 'port_num' set but not used [-Wunused-but-set-variable]
mv_eth.c: In function 'mv64460_eth_print_stat':
mv_eth.c:1010:15: warning: variable 'port_num' set but not used [-Wunused-but-set-variable]
mv_eth.c: In function 'eth_clear_mib_counters':
mv_eth.c:2067:15: warning: variable 'dummy' set but not used [-Wunused-but-set-variable]
sdram_init.c: In function 'check_dimm':
sdram_init.c:289:50: warning: variable 'trrd_clocks' set but not used [-Wunused-but-set-variable]
sdram_init.c:289:37: warning: variable 'tras_clocks' set but not used [-Wunused-but-set-variable]
sdram_init.c:289:24: warning: variable 'trcd_clocks' set but not used [-Wunused-but-set-variable]
sdram_init.c:289:8: warning: variable 'trp_clocks' set but not used [-Wunused-but-set-variable]
sdram_init.c:279:34: warning: variable 'devicesForErrCheck' set but not used [-Wunused-but-set-variable]
sdram_init.c: In function 'setup_sdram':
sdram_init.c:1255:13: warning: variable 'check' set but not used [-Wunused-but-set-variable]
sdram_init.c: In function 'initdram':
sdram_init.c:1744:25: warning: variable 'check' set but not used [-Wunused-but-set-variable]
sdram_init.c:1742:14: warning: variable 's1' set but not used [-Wunused-but-set-variable]
sdram_init.c:1742:6: warning: variable 's0' set but not used [-Wunused-but-set-variable]

Note: no attempt was make to clean up the mess coding style and
other issues in sdram_init.c

Signed-off-by: Wolfgang Denk <wd@denx.de>