[video_core/vic] remove handrolled vector implementation that also uses software prefetching(!!!!); don't try to outsmart compiler - also remove template spam (#2856)

Also removes sse2neon :)
Software prefetching SUCKS and it's evil don't do it
Signed-off-by: lizzie <lizzie@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2856
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: Caio Oliveira <caiooliveirafarias0@gmail.com>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

externals/cpmfile.json

@@ -213,14 +213,5 @@
         "key": "steamdeck",
         "bundled": true,
         "skip_updates": "true"
-    },
-    "sse2neon": {
-        "repo": "DLTcollab/sse2neon",
-        "sha": "66267b52fd",
-        "hash": "3aed8676e1b8c428acb076464663e3968a721457b08710a7c5f8df2fbdaa5601053c1606169a55e987e7a58dd17e3cc3b7fbf953aa891c5ac5f8ce2941862e4b",
-        "download_only": "true",
-        "patches": [
-            "0001-Add-support-for-clang-cl-on-Windows-633.patch"
-        ]
     }
 }