RPi: just use RPI instead of RPI2.

The reason for this change is that RPi2 and RPi3 are compatible, and
hopefully all differences coming up can be resolved without ifdefs but
at runtime.

cmake/configs/posix_rpi_common.cmake

@@ -1,12 +1,12 @@
-# This file is shared between posix_rpi2_native.cmake
-# and posix_rpi2_cross.cmake.
+# This file is shared between posix_rpi_native.cmake
+# and posix_rpi_cross.cmake.
 
 include(posix/px4_impl_posix)
 
 # This definition allows to differentiate if this just the usual POSIX build
 # or if it is for the RPi.
 add_definitions(
-	-D__PX4_POSIX_RPI2
+	-D__PX4_POSIX_RPI
 	-D__LINUX
 )
 

cmake/configs/posix_rpi_cross.cmake

@@ -1,4 +1,4 @@
-include(configs/posix_rpi2_common)
+include(configs/posix_rpi_common)
 
 set(CMAKE_TOOLCHAIN_FILE ${CMAKE_SOURCE_DIR}/cmake/toolchains/Toolchain-arm-linux-gnueabihf-raspbian.cmake)
 

cmake/configs/posix_rpi_native.cmake

@@ -1,3 +1,3 @@
-include(configs/posix_rpi2_common)
+include(configs/posix_rpi_common)
 
 set(CMAKE_TOOLCHAIN_FILE ${CMAKE_SOURCE_DIR}/cmake/toolchains/Toolchain-native.cmake)

cmake/toolchains/Toolchain-arm-linux-gnueabihf-raspbian.cmake

@@ -71,7 +71,7 @@ foreach(tool echo grep rm mkdir nm cp touch make unzip)
 endforeach()
 
 add_definitions(
-	-D __RPI2
+	-D __RPI
 	)
 
 set(LINKER_FLAGS "-Wl,-gc-sections")