You can edit the file to remove the line you added and that should have your sound back to normal (although still without working headphone jack sensing).
Before removing the line, I would try changing 'hp' (which is an invalid keyword) to 'hp-dv5' since that's the closest match for your model (and then rebooting).
gksu gedit /etc/modprobe.d/alsa-base.conf
In case you're wondering, the full list for that codec is here:
ref Reference board
dell-m4-1 Dell desktops
dell-m4-2 Dell desktops
dell-m4-3 Dell desktops
hp-m4 HP mini 1000
hp-dv5 HP dv series
hp-hdx HP HDX series
hp-dv4-1222nr HP dv4-1222nr (with LED support)
auto BIOS setup (default)