[HAL][EXTI] Optimize computation of pExtiConfig->GPIOSel in HAL_EXTI_GetConfigLine()

Src/stm32f7xx_hal_exti.c

diff --git a/Src/stm32f7xx_hal_exti.c b/Src/stm32f7xx_hal_exti.c
index c43c1da..52e5687 100644
--- a/Src/stm32f7xx_hal_exti.c
+++ b/Src/stm32f7xx_hal_exti.c
@@ -301,7 +301,7 @@
       assert_param(IS_EXTI_GPIO_PIN(linepos));
 
       regval = SYSCFG->EXTICR[linepos >> 2u];
-      pExtiConfig->GPIOSel = ((regval << (SYSCFG_EXTICR1_EXTI1_Pos * (3uL - (linepos & 0x03u)))) >> 24);
+      pExtiConfig->GPIOSel = (regval >> (SYSCFG_EXTICR1_EXTI1_Pos * (linepos & 0x03u))) & SYSCFG_EXTICR1_EXTI0;
     }
   }