You must use the appropriate SYSROOT path for the design.
To build the host application, run the following command:
aarch64-linux-gnu-g++ -Wall -c -std=c++14 -Wno-int-to-pointer-cast \
--sysroot=${SDKTARGETSYSROOT} \
-I$(SDKTARGETSYSROOT)/usr/include/xrt \
-I-I$(SDKTARGETSYSROOT)/usr/include \
-o host.o host.cpp
aarch64-linux-gnu-g++ *.o -lxrt_coreutil \
--sysroot=${SDKTARGETSYSROOT} \
-std=c++14 -o host.exe
or
make host