tests: use STM32 Nucleo-64 name in readmes

tests/driver_dsp0401/README.md

@@ -12,7 +12,7 @@ The display can be controlled from the JP1 connection jumper as follows:
 * Connect `PWM` to the board `DSP0401_PARAM_PWM_DEV` pwm device. See the board periph_conf.h
 to find a valid pin and configuration.
 * Connect `VCC` to one of the board VCC pin (3.3V or 5V depending on your board.
-  Example: use 3.3V with ST Nucleo)
+  Example: use 3.3V with STM32 Nucleo-64)
 * Connect `GND` to one of the board GND.
 
 Since there are potentially a lot of LEDs to poweron, it's preferable to use an

tests/driver_sx127x/README.md

@@ -3,7 +3,7 @@
 This is a manual test application for the SX127X radio driver.
 
 This test application uses the default pin configuration provided by the
-driver implementation and that matches the ST Nucleo 64 pins layout.
+driver implementation and that matches the STM32 Nucleo-64 layout.
 It is best to use [SX1272](https://developer.mbed.org/components/SX1272MB2xAS/)
 or [SX1276](https://developer.mbed.org/components/SX1276MB1xAS/) mbed modules
 with nucleo boards or the all-in-one

tests/pkg_semtech-loramac/README.md

@@ -40,7 +40,7 @@ use the `set`/`get` commands in test application shell.
 ### Building the application
 
 The default parameters for the Semtech SX1272/SX1276 radios works as-is with
-ST Nucleo 64 boards and MBED LoRa shields
+STM32 Nucleo-64 boards and MBED LoRa shields
 ([SX1276](https://os.mbed.com/components/SX1276MB1xAS/) or
 [SX1272](https://os.mbed.com/components/SX1272MB2xAS/)). You can also use the
 ST [b-l072z-lrwan1](http://www.st.com/en/evaluation-tools/b-l072z-lrwan1.html)