modules: nrf_wifi: Include OSAL lib in buslib compilation

With introduction of OSAL wrapper for memory allocation, usage of
zephyr's native malloc calls need to be removed. When NRF70 driver
is not enabled, OSAL needs to be built explicitly.

Signed-off-by: Ravi Dondaputi <ravi.dondaputi@nordicsemi.no>

modules/nrf_wifi/bus/CMakeLists.txt

@@ -9,15 +9,23 @@ if(NOT DEFINED ENV{ZEPHYR_BASE})
     message(FATAL_ERROR "ZEPHYR_BASE environment variable is not set. Please set it to the Zephyr base directory.")
 endif()
 
+set(NRF_WIFI_DIR ${ZEPHYR_CURRENT_MODULE_DIR})
+
 if (CONFIG_NRF70_BUSLIB)
   zephyr_library_named(nrf70-buslib)
   zephyr_library_include_directories(
     inc
+    ${NRF_WIFI_DIR}/os_if/inc
   )
   zephyr_library_sources(
     rpu_hw_if.c
     device.c
   )
+  if(NOT CONFIG_WIFI_NRF70)
+    zephyr_library_sources(
+      ${NRF_WIFI_DIR}/os_if/src/osal.c
+    )
+  endif()
   zephyr_library_sources_ifdef(CONFIG_NRF70_ON_QSPI
     qspi_if.c
   )