SiLabs: GPIO interrupts disabled/enabled incorrectly

GPIO_IntEnable/Disable was called with incorrect params due
to missing parens. Operator precedence of & vs << caused the
call to be blank if the port (MSB) nibble of pin was not zero.

Author: mpolojar

libraries/mbed/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/gpio_irq_api.c

@@ -147,7 +147,7 @@ void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable)
     bool was_disabled = false;
     if(GPIO->IEN == 0) was_disabled = true;
 
-    GPIO_IntConfig((GPIO_Port_TypeDef)(obj->pin >> 4 & 0xF), obj->pin &0xF, obj->risingEdge, obj->fallingEdge, obj->risingEdge || obj->fallingEdge);
+    GPIO_IntConfig((GPIO_Port_TypeDef)((obj->pin >> 4) & 0xF), obj->pin &0xF, obj->risingEdge, obj->fallingEdge, obj->risingEdge || obj->fallingEdge);
     if ((GPIO->IEN != 0) && (obj->risingEdge || obj->fallingEdge) && was_disabled) {
         blockSleepMode(GPIO_LEAST_ACTIVE_SLEEPMODE);
     }
@@ -156,12 +156,12 @@ void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable)
 inline void gpio_irq_enable(gpio_irq_t *obj)
 {
     if(GPIO->IEN == 0) blockSleepMode(GPIO_LEAST_ACTIVE_SLEEPMODE);
-    GPIO_IntEnable(1 << obj->pin & 0xF); // pin mask for pins to enable
+    GPIO_IntEnable(1 << (obj->pin & 0xF)); // pin mask for pins to enable
 }
 
 inline void gpio_irq_disable(gpio_irq_t *obj)
 {
-    GPIO_IntDisable(1 << obj->pin & 0xF); // pin mask for pins to disable
+    GPIO_IntDisable(1 << (obj->pin & 0xF)); // pin mask for pins to disable
     if(GPIO->IEN == 0) unblockSleepMode(GPIO_LEAST_ACTIVE_SLEEPMODE);
 }