I would like to know which of the .h files below are required.
what is the minimum required .h files from below ?
I put all these files in a folder called “.global_conf”.
Hi, you should not be copying any individual .h files except lv_conf.h. Copy it to your components folder. All other h files will be accessed from the components/lvgl or components/drv folders. Copy those whole directories to your components directory. Note that if your project is using CMake, you will get warnings about missing h files but moving those around will only mean you get a link error instead. You need to build using make, and you need to follow the instruction to copy the lv_component.mk file to the lvgl folder.
Deleting any LittlevGL header file is a bad practice. You should not need to modify the contents of the lvgl directory at all.
You need your own copies of lv_conf.h and lv_ex_conf.h somewhere in your project. Technically, you can then delete the template versions, but again, I advise keeping them around to avoid having a different tree than what is on GitHub. That will make it harder for you to update/us to know what has changed later if you need help with something.
@jeremyjh is correct. The only two files you need to copy (ideally out of the lvgl folder) are the template files (which then have to be renamed). You should then be able to leave the lvgl folder as is. No further changes are necessary.