manifest: update hal_rpi_pico to 2.1.0 release

This version of the HAL is based on the 2.1.0 release of the Raspberry
Pi Pico SDK.

Update `modules/hal_rpi_pico/CMakeLists.txt` to add the new include
directories to the build. See https://github.com/raspberrypi/pico-sdk/releases/tag/2.1.0


for more information.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@gmail.com>
Signed-off-by: Andrew Featherstone <andrew.featherstone@gmail.com>