fix: file svg_bios.u49 under the svgpcb set

svg_bios.u49 is listed in svgpcbBIOSRomDesc (d_pgm.cpp:923-929), which only
STDROMPICKEXT(svgpcb, svgpcb, svgpcbBIOS) at line 7035 pulls in. The FBNeo
DAT likewise places it in svgpcb, and pgm's own list (pgmRomDesc, lines
879-892) has six members. The fbneo profile now files it under svgpcb.zip.

bios/Arcade/Arcade/pgm.zip is rebuilt as TorrentZip from the six members of
the FBNeo pgm recipe. The build is byte for byte the copy that was in
.variants/pgm.zip.6bbbce09, which goes. The two unpinned seven-member
copies (.variants/pgm.zip.931a4971 and MAME/.variants/pgm.zip.6ade4934)
go too: every member is still held, svg_bios.u49 as
bios/Arcade/FBNeo/svg_bios.u49. The pinned copies (87cc944e in MAME/,
68ef99a1 in .variants/) are untouched.

emulators/fbneo.yml

@@ -588,13 +588,13 @@ files:
     source_ref: "upstream src/burn/drv/pgm/d_pgm.cpp:887"
 
   - name: "svg_bios.u49"
-    archive: pgm.zip
+    archive: svgpcb.zip
     system: igs-pgm
     required: false
     size: 131072
     crc32: "3346401f"
-    note: "68K BIOS V0001 custom (05/13/05) for SVG PCB"
-    source_ref: "upstream src/burn/drv/pgm/d_pgm.cpp:928"
+    note: "68K BIOS V0001 custom (05/13/05) for SVG PCB, in the svgpcb ROM list"
+    source_ref: "upstream src/burn/drv/pgm/d_pgm.cpp:928, 7035"
 
   # -------------------------------------------------------
   # Capcom CPS-3 (per-game BIOS, no shared archive)