Does not build with latest pico-sdk

[vschlegel]

seems like the latest pico-sdk 2.0.0 broke the building process.

steps to reproduce:

mkdir test
cd test
sudo apt install cmake gcc-arm-none-eabi libnewlib-arm-none-eabi libstdc++-arm-none-eabi-newlib
git clone https:/scottalford75/Remora-RP2040-W5500
cd Remora-RP2040-W5500
mkdir build
cd build
export PICO_SDK_FETCH_FROM_GIT=TRUE
cmake -DPICO_BOARD=pico_w ..
cmake -DCMAKE_BUILD_TYPE=Debug . -DPICO_BOARD=pico
make clean
make

this fails in:

[ 23%] Building C object port/CMakeFiles/LWIP_FILES.dir/__/_deps/pico_sdk-src/src/rp2_common/pico_bootrom/bootrom.c.obj
/home/val/test/Remora-RP2040-W5500/build/_deps/pico_sdk-src/src/rp2_common/pico_bootrom/bootrom.c:9:10: fatal error: boot/picobin.h: No such file or directory
    9 | #include "boot/picobin.h"
      |          ^~~~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [port/CMakeFiles/LWIP_FILES.dir/build.make:1462: port/CMakeFiles/LWIP_FILES.dir/__/_deps/pico_sdk-src/src/rp2_common/pico_bootrom/bootrom.c.obj] Error 1
make[1]: *** [CMakeFiles/Makefile2:2303: port/CMakeFiles/LWIP_FILES.dir/all] Error 2
make: *** [Makefile:91: all] Error 2

my workaroud:

1. delete the /build directory
2. in pico_sdk_import.cmake, change GIT_TAG masteŗ to GIT_TAG 1.5.1 in lines 37 and 44
3. go trough the build process listed above