openthread: add soft float fallback for lib path calculation

Add soft float fallback to enable building from libs with softfp
ABI enabled.

Code built with `soft` and `softfp` `float-abi` options
can be linked together as they both use the same soft-float ABI
and generate functions to pass floating-point arguments
to integer registers.
This is contrary to the `hard` option where floating-point arguments
are passed directly to FPU registers.
`softfp` additionally allows using hardware floating-point
instructions instead of emulated ones.

Signed-off-by: Maciej Baczmanski <[email protected]>

openthread/cmake/extensions.cmake

@@ -7,6 +7,8 @@
 # The Build the path of the library taking in nrf_security backend type,
 # OpenThread version and feature set
 function(openthread_calculate_lib_path ot_version lib_path)
+  set(OPENTHREAD_LIB_BASE_DIR "${ZEPHYR_NRFXLIB_MODULE_DIR}/openthread")
+
   if(CONFIG_OPENTHREAD_NORDIC_LIBRARY_MASTER)
     set(ot_feature_set "master")
   elseif(CONFIG_OPENTHREAD_NORDIC_LIBRARY_FTD)
@@ -19,14 +21,15 @@ function(openthread_calculate_lib_path ot_version lib_path)
     set(ot_feature_set "custom")
   endif()
 
-  nrfxlib_calculate_lib_path(nrfxlib_path)
+  nrfxlib_calculate_lib_path(nrfxlib_path BASE_DIR ${OPENTHREAD_LIB_BASE_DIR} SOFT_FLOAT_FALLBACK)
+
   if(CONFIG_OPENTHREAD_COPROCESSOR_RCP)
     set(${lib_path}
-      "${ZEPHYR_NRFXLIB_MODULE_DIR}/openthread/${nrfxlib_path}/${ot_version}/rcp"
+      "${nrfxlib_path}/${ot_version}/rcp"
       PARENT_SCOPE)
   else()
     set(${lib_path}
-      "${ZEPHYR_NRFXLIB_MODULE_DIR}/openthread/${nrfxlib_path}/${ot_version}/${ot_feature_set}/${nrf_security_backend}"
+      "${nrfxlib_path}/${ot_version}/${ot_feature_set}/${nrf_security_backend}"
       PARENT_SCOPE)
   endif()