You could redefine it after loading hyperref:
pd1enc.def (PDFDocEncoding definition file) and
puenc.def (PDF Unicode definition file) define
If you make your redefinition later, i.e. after loading hyperref, yours will override the previous ones.
The problem here shows, that it's better to try using unique names, even if they are longer. Short and common names are often already used. Furthermore, you don't need to lose the
\L brought by hyperref. Although it's just an
\L, I explain this because similar things can happen with other macros you might need.