F103 devices: Set CAN_RD pins in Input mode instead of A/F Push-Pull

Now MBED_A27/A28 tests are OK again.
Problem seen also by @mgiaco and discussed in PR 2988.

Author: bcostm

targets/TARGET_STM/TARGET_STM32F1/TARGET_BLUEPILL_F103C8/PeripheralPins.c

@@ -167,8 +167,8 @@ const PinMap PinMap_SPI_SSEL[] = {
 };
 
 const PinMap PinMap_CAN_RD[] = {
-    {PA_11, CAN_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_NOPULL, 0)},
-    {PB_8 , CAN_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_NOPULL, 1)},
+    {PA_11, CAN_1, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0)},
+    {PB_8 , CAN_1, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 1)},
     {NC,    NC,    0}
 };
 

targets/TARGET_STM/TARGET_STM32F1/TARGET_NUCLEO_F103RB/PeripheralPins.c

@@ -181,8 +181,8 @@ const PinMap PinMap_SPI_SSEL[] = {
 };
 
 const PinMap PinMap_CAN_RD[] = {
-    {PA_11, CAN_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_NOPULL, 0)},
-    {PB_8 , CAN_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_NOPULL, 10)}, // Remap CAN_RX to PB_8
+    {PA_11, CAN_1, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0)},
+    {PB_8 , CAN_1, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 10)}, // Remap CAN_RX to PB_8
     {NC,    NC,    0}
 };