Hello, yes you can upgrade your CPU in that laptop. I give you a list of some examples. I don't recommend to buy the QM cpus from the list cause you may have thermal problems if you push hard the laptop. For normal usage the quad core chip should work fine.
Intel® Core™ i7-2670QM (2.20 GHz, 6 MB L3 cache) ( Quad core )
Intel® Core™ i7-2630QM (2.00 GHz, 6 MB L3 cache) ( Quad core )
Intel® Core™ i7-2620M (2.70 GHz, 4 MB L3 cache) ( Dual core )
Intel® Core™ i5-2540M (2.60 GHz, 3 MB L3 cache) ( Dual core )