manu,
You can try with the following:
#define LED1 (GPIO_PORT_A | GPIO_PIN11)
#define LED2 (GPIO_PORT_A | GPIO_PIN28)
#define LED3 (GPIO_PORT_A | GPIO_PIN29)
#define LED4 (GPIO_PORT_A | GPIO_PIN10)
Note that you need to specify the port, in this case, port A and the pin.
Also MQX already has these definitions. If you're interested in using them, these are:
BSP_LED1
BSP_LED2
BSP_LED3
BSP_LED4
You can find them on the "twrk60n512.h" file at:
{MQX path}\lib\twrk60n512.cw10\bsp
Note that the specific BSP folder may change if you're using a different toolchain (IAR or Keil)