build: add correct flags to efl-one.pc

they are required, and normally dragged in via eina.

meson.build

@@ -504,7 +504,7 @@ if (get_option('efl-one'))
   pkgconfig.generate(
     name : 'efl-one',
     description: 'Configureation for efl in one big fat .so',
-    libraries : efl_one,
+    libraries : [efl_one] + eina_pc_deps, #eina is a special case here which drags in m dl & threads
   )
 
   #overwrite all the dependencies of subprojects with efl-one, in order to link the modules and binaries to the correct .so

src/lib/eina/meson.build

@@ -1,6 +1,7 @@
 eina_deps = [dl]
 eina_pub_deps = [thread_dep]
-eina_ext_deps = [m, rt, dl, thread_dep]
+eina_pc_deps = [m, rt, dl, thread_dep] #special case, this array is taken to drag in external deps to efl-one
+eina_ext_deps = eina_pc_deps
 
 if sys_windows == true
    eina_pub_deps += [evil]
@@ -393,5 +394,5 @@ pkgconfig.generate(eina_lib,
   name : 'eina',
   subdirs : ['eina-'+version_major, 'efl-'+version_major, join_paths('eina-'+version_major, 'eina')],
   version : version_major + '.' + version_minor + '.' + version_micro,
-  libraries : eina_pub_deps,
+  libraries : eina_pub_deps + eina_pc_deps,
 )