PPSSPP installation does not create memory card save file directories

[sakuramboo]

### Environment information

- Steam version: Latest
- OS: Ubuntu and SteamOS
- RetroArch version: Stable
- CPU: N/A
- GPU: N/A
- Video/Audio/Input driver: N/A

## Description
After installing PPSSPP through the DLC manager, the memory card save location does not get created. On both my desktop (Ubuntu 18.04) and the Steam Deck I had to manually create the following directories...

saves/PSP/Cheats
saves/PSP/flash0
saves/PSP/GAME
saves/PSP/PPSSPP_STATE
saves/PSP/SAVEDATA
saves/PSP/SYSTEM/CACHE

I'm not sure if all of the directories are needed, but that's what's outlined on libretro's website. Because they were manually created, they don't utilize cloud saves.

### Expected behavior
The directories should be created like it is for other emulators that require a dedicated folder structure.

### Actual behavior
Directories don't get created.

### Steps to reproduce the bug
1. Install PPSSPP
2. Check if directories exist

### Troubleshooting Steps / Actions Taken
I did this twice, once on my desktop and once on the Steam Deck. I had to manually create the directories both times. If the directories don't exist, any game I run complains that there isn't enough space on the memory card. Once I create the directories, it works. But, lacks the cloud saving feature. I'm not sure if all that's needed is to add the steam_autocloud.vdf file to each directory or if that would even work.

### Log