profiles/gap: Change len parameter of name2utf8() to uint16_t
profiles/gap: Change len parameter of name2utf8() to uint16_t

When device name is read its length is of type uint16_t, change the type
of length parameter of name2utf8() to uint16_t to avoid unnecessary
truncation.

silent-snowman/bluez,pkarasev3/bluez,ComputeCycles/bluez,pkarasev3/bluez,silent-snowman/bluez,ComputeCycles/bluez,mapfau/bluez,ComputeCycles/bluez,pkarasev3/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,pkarasev3/bluez,ComputeCycles/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,mapfau/bluez,silent-snowman/bluez