add new flag to build instructions (#78)

This flag is required to link a pytorch use-case correctly.
It doesn't seem to impact the rocSHMEM code.

[ROCm/rocshmem commit: 5e49567b6c]

projects/rocshmem/scripts/build_configs/ipc_single

@@ -15,6 +15,7 @@ cmake \
     -DCMAKE_BUILD_TYPE=Release \
     -DCMAKE_INSTALL_PREFIX=$install_path \
     -DCMAKE_VERBOSE_MAKEFILE=OFF \
+    -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
     -DDEBUG=OFF \
     -DPROFILE=OFF \
     -DUSE_RO=OFF \

projects/rocshmem/scripts/build_configs/ro_ipc

@@ -15,6 +15,7 @@ cmake \
     -DCMAKE_BUILD_TYPE=Release \
     -DCMAKE_INSTALL_PREFIX=$install_path \
     -DCMAKE_VERBOSE_MAKEFILE=OFF \
+    -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
     -DDEBUG=OFF \
     -DPROFILE=OFF \
     -DUSE_IPC=ON \

projects/rocshmem/scripts/build_configs/ro_net

@@ -15,6 +15,7 @@ cmake \
     -DCMAKE_BUILD_TYPE=Release \
     -DCMAKE_INSTALL_PREFIX=$install_path \
     -DCMAKE_VERBOSE_MAKEFILE=OFF \
+    -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
     -DDEBUG=OFF \
     -DPROFILE=OFF \
     -DUSE_IPC=OFF \