m48t59: fix write access

Fix incorrect order of arguments, letting writes to NVRAM succeed.

It looks like guests never write to the device, only read from it, since the bug
originates back to 819385c5.
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

hw/m48t59.c

@@ -491,7 +491,7 @@ static void NVRAM_writeb (void *opaque, uint32_t addr, uint32_t val)
         NVRAM->addr |= val << 8;
         break;
     case 3:
-        m48t59_write(NVRAM, val, NVRAM->addr);
+        m48t59_write(NVRAM, NVRAM->addr, val);
         NVRAM->addr = 0x0000;
         break;
     default: