CMake: support "make programs"

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/programs/pkey/CMakeLists.txt b/programs/pkey/CMakeLists.txt
index cd0387a..defbe28 100644
--- a/programs/pkey/CMakeLists.txt
+++ b/programs/pkey/CMakeLists.txt
@@ -2,6 +2,7 @@
     dh_client
     dh_server
 )
+add_dependencies(${programs_target} ${executables_mbedtls})
 
 foreach(exe IN LISTS executables_mbedtls)
     add_executable(${exe} ${exe}.c $<TARGET_OBJECTS:mbedtls_test>)
@@ -29,6 +30,7 @@
     rsa_verify
     rsa_verify_pss
 )
+add_dependencies(${programs_target} ${executables_mbedcrypto})
 
 foreach(exe IN LISTS executables_mbedcrypto)
     add_executable(${exe} ${exe}.c $<TARGET_OBJECTS:mbedtls_test>)