Add SPI::setMOSI/setMISO, better match pin names (#2166)

docs/spi.rst

@@ -8,10 +8,10 @@ SPI pinouts can be set **before SPI.begin()** using the following calls:
 
 .. code:: cpp
 
-    bool setRX(pin_size_t pin);
+    bool setRX(pin_size_t pin); // or setMISO()
     bool setCS(pin_size_t pin);
     bool setSCK(pin_size_t pin);
-    bool setTX(pin_size_t pin);
+    bool setTX(pin_size_t pin); // or setMOSI()
 
 Note that the ``CS`` pin can be hardware or software controlled by the sketch.
 When software controlled, the ``setCS()`` call is ignored.

libraries/SPI/src/SPI.h

@@ -45,9 +45,15 @@ public:
 
     // Assign pins, call before begin()
     bool setRX(pin_size_t pin);
+    inline bool setMISO(pin_size_t pin) {
+        return setRX(pin);
+    }
     bool setCS(pin_size_t pin);
     bool setSCK(pin_size_t pin);
     bool setTX(pin_size_t pin);
+    bool setMOSI(pin_size_t pin) {
+        return setTX(pin);
+    }
 
     // Call once to init/deinit SPI class, select pins, etc.
     virtual void begin() override {