The Mobile Turion x64 MT, ML34 uses a laptop motherboard socket 754 which doesn't seem to be a soldered on processor. So you most likely can upgrade the processor.
Here are the specs for your Turion x64: http://www.cpu-world.com/CPUs/K8/AMD-Turion%2064%20Mobile%20technology%20ML-34%20-%20TMDML34BKX5LD.h...
Here is a list that shows all Socket 754 AMD Processors: http://www.cpu-world.com/Related_CPUs/Socket%20754_K8.html ( I just posted a partial list of all those that are faster than the processor you now have):
But you can't just find the fastest on the list and install it in your laptop. Your Motherboard & BIOS must support whatever CPU you upgrade to.
Therefore you need to open a HP Support ticket and find out exactly which Mobile socket 754 processor your Motherboard and BIOS in your laptop supports.
All the processors in the above CPU World list will fit in your laptop's socket 754, but if it isn't supported, you laptop will not power up. You will have a dead weight.
Only HP Support or possibly a Moderator in HP Forums can tell you which processor you can upgrade to that is supported by your specific laptop.