lr-hatari: fix core build due to upstream changes

[cmitu]

Upstream started incorporating the latest Hatari version into the core and renamed the previouos core version to hatari2014. Until the merge is complete and stable, use the old version, now in a separate branch.

Modified the build to:

• use the CAPSIMG variables that are now part of the upstream makefile, instead of using our own
• update our patch to exclude our link/include flags for CAPSIMG in the makefile and fix the core name
• use -rpath linker option to have the core .so library search for the campsimg library in the install folder (similar to how the standalone emulator build recipe does). This alows us to get rid of the configure modifications to emulators.cfg for setting LD_LIBRARY_PATH

Notes:

• I have a version for the new core in https://github.com/cmitu/RetroPie-Setup/tree/lr-hatari--4, but I noticed there are a few issues opened for it, that's why I kept the 'old' source of the core in these modifications. We might use it in the future and rename this module to lr-hatari2014.
• The branch name is correct, the upstream repo mis-spelled hatari when creating the 2014 branch.

[cmitu]

I've set the PR to draft for now, since our patch may have to be modified again, pending some upstream changes.

[cmitu]

OK, reworked the patch, taking into account latest libretro branch changes, and removed our patch entirely. Edited the PR's description to match the commit changes.