stdlib: Drop duplicates of min() and max()

Change-Id: Ib2f6fad735e085d237a0d46e0586e123eef6e0e2
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/6161
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>

src/northbridge/intel/gm45/raminit.c

@@ -20,6 +20,7 @@
  */
 
 #include <stdint.h>
+#include <stdlib.h>
 #include <arch/cpu.h>
 #include <arch/io.h>
 #include <device/pci_def.h>
@@ -361,7 +362,6 @@ static void collect_ddr3(spdinfo_t *const config)
 	}
 }
 
-#define min(a, b) ((a) < (b))?(a):(b)
 #define ROUNDUP_DIV(val, by) (((val) + (by) - 1) / (by))
 #define ROUNDUP_DIV_THIS(val, by) val = ROUNDUP_DIV(val, by)
 static fsb_clock_t read_fsb_clock(void)