[FK407M1] Add missing PA15 definition

Signed-off-by: Frederic.Pillon <frederic.pillon@st.com>

Author: fpistm

variants/FK407M1/variant.cpp

@@ -80,7 +80,7 @@ const PinName digitalPin[] = {
   PD_6,   PD_7,
   PC_7,   PC_8,
   PD_15,  PC_6,
-  PC_13, // LED pin - not broken out on the board
+  PC_13,  PA_15, // LED and Button pins - not broken out on the board
   // Analog pins
   PA_0,
   PA_1,

variants/FK407M1/variant.h

@@ -121,11 +121,13 @@ extern const PinName digitalPin[];
 #define PD15 72
 #define PC6  73
 #define PC13 74
+#define PA15 75
+
 // This must be a literal
-#define NUM_DIGITAL_PINS        91
+#define NUM_DIGITAL_PINS        92
 // This must be a literal with a value less than or equal to MAX_ANALOG_INPUTS
 #define NUM_ANALOG_INPUTS       16
-#define NUM_ANALOG_FIRST        75
+#define NUM_ANALOG_FIRST        76
 
 // On-board LED pin number
 #define LED_D1                  PC13