What’s needed for a mobile phone mount (7)
I believe the answer is:
charger
I believe this is a double definition.
'what's needed for a mobile phone' is the first definition.
(a phone charger)
'mount' is the second definition.
(type of horse)
(Other definitions for charger that I've seen before include "One loading" , "Horse - plate" , "Electrical device - old warhorse" , "One may provide juice" , "Type of platter" .)