Mega Man Legends 2: PSP Improvements

This is a hack for the PS1 version of Mega Man Legends 2 that replicates a couple of adjustments the game got for the japan-exclusive PSP port.

-Normal FPS while underwater: the lower FPS mode used for the underwater effect has been removed.
-Normal walking acceleration while underwater: the slowed down acceleration at the start of any walk cycle while underwater has been removed.
-Reduced weapon upgrades prices: the weapons upgrades price list was imported directly from the PSP version.