We claim the ornamental design for a mobile phone, as shown and described.
FIG. 1 is a perspective view of a mobile phone showing the new design:
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a left-side elevation view thereof;
FIG. 5 is a right-side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines showing the remainder of the mobile phone are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.