Build: Use new-style syntax in link-libraries

Migrate to new syntax where the PUBLIC attribute is explicitly defined.
Avoids issues caused sometimes where cmake does not allow the mixing of
old-style and new-style syntax

Signed-off-by: Raef Coles <raef.coles@arm.com>
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index f0315f7..8962555 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -180,29 +180,29 @@
 if(USE_STATIC_MBEDTLS_LIBRARY)
     add_library(${mbedcrypto_static_target} STATIC ${src_crypto})
     set_target_properties(${mbedcrypto_static_target} PROPERTIES OUTPUT_NAME mbedcrypto)
-    target_link_libraries(${mbedcrypto_static_target} ${libs})
+    target_link_libraries(${mbedcrypto_static_target} PUBLIC ${libs})
 
     add_library(${mbedx509_static_target} STATIC ${src_x509})
     set_target_properties(${mbedx509_static_target} PROPERTIES OUTPUT_NAME mbedx509)
-    target_link_libraries(${mbedx509_static_target} ${libs} ${mbedcrypto_static_target})
+    target_link_libraries(${mbedx509_static_target} PUBLIC ${libs} ${mbedcrypto_static_target})
 
     add_library(${mbedtls_static_target} STATIC ${src_tls})
     set_target_properties(${mbedtls_static_target} PROPERTIES OUTPUT_NAME mbedtls)
-    target_link_libraries(${mbedtls_static_target} ${libs} ${mbedx509_static_target})
+    target_link_libraries(${mbedtls_static_target} PUBLIC ${libs} ${mbedx509_static_target})
 endif(USE_STATIC_MBEDTLS_LIBRARY)
 
 if(USE_SHARED_MBEDTLS_LIBRARY)
     add_library(${mbedcrypto_target} SHARED ${src_crypto})
     set_target_properties(${mbedcrypto_target} PROPERTIES VERSION 2.24.0 SOVERSION 5)
-    target_link_libraries(${mbedcrypto_target} ${libs})
+    target_link_libraries(${mbedcrypto_target} PUBLIC ${libs})
 
     add_library(${mbedx509_target} SHARED ${src_x509})
     set_target_properties(${mbedx509_target} PROPERTIES VERSION 2.24.0 SOVERSION 1)
-    target_link_libraries(${mbedx509_target} ${libs} ${mbedcrypto_target})
+    target_link_libraries(${mbedx509_target} PUBLIC ${libs} ${mbedcrypto_target})
 
     add_library(${mbedtls_target} SHARED ${src_tls})
     set_target_properties(${mbedtls_target} PROPERTIES VERSION 2.24.0 SOVERSION 13)
-    target_link_libraries(${mbedtls_target} ${libs} ${mbedx509_target})
+    target_link_libraries(${mbedtls_target} PUBLIC ${libs} ${mbedx509_target})
 endif(USE_SHARED_MBEDTLS_LIBRARY)
 
 foreach(target IN LISTS target_libraries)