Modify RPi3 and RPi4 unified formats

05_drivers_gpio_uart/README.md

@@ -87,7 +87,7 @@ following.**
 arm_64bit=1
 init_uart_clock=48000000
 ```
-### Pi 3
+### RPi 3
 
 3. Copy the following files from the [Raspberry Pi firmware repo](https://github.com/raspberrypi/firmware/tree/master/boot) onto the SD card:
     - [bootcode.bin](https://github.com/raspberrypi/firmware/raw/master/boot/bootcode.bin)
@@ -95,7 +95,7 @@ init_uart_clock=48000000
     - [start.elf](https://github.com/raspberrypi/firmware/raw/master/boot/start.elf)
 4. Run `make`.
 
-### Pi 4
+### RPi 4
 
 3. Copy the following files from the [Raspberry Pi firmware repo](https://github.com/raspberrypi/firmware/tree/master/boot) onto the SD card:
     - [fixup4.dat](https://github.com/raspberrypi/firmware/raw/master/boot/fixup4.dat)