Add missing IMPORT_C to two functions, to match the EXPORT_C in the corresponding cpp files
EXPORTS
_ZN19CSpbContentProvider11GetContentLER16MVPbkContactLinkRP7HBufC16R11TPbk2IconIdRNS_15TSpbContentTypeE @ 1 NONAME
_ZN19CSpbContentProvider12AddObserverLER27MSpbContentProviderObserver @ 2 NONAME
_ZN19CSpbContentProvider14RemoveObserverER27MSpbContentProviderObserver @ 3 NONAME
_ZN19CSpbContentProvider19CreateServiceIconLCERK11TPbk2IconId @ 4 NONAME
_ZN19CSpbContentProvider4NewLER19CVPbkContactManagerR17CPbk2StoreManagerl @ 5 NONAME