sony/smc777.cpp: misc fixes:

* reverse palette offsets and add gfx pal bank (demofd4)
* add default palette for non-color board pal bank (side effect of above)
* add reverse hookup for text layer (amazon), add FRC hookup
* disable cursor if out of range (sys12j:BIRD, transitt)
* add set_raw in place of legacy screen setup (makes transitt scroll less jerky)
* BREAKING CHANGE: replace floppy option from ssdd to 35ssdd string

Systems promoted to working
---------------------------
SMC-777 [Angelo Salese]

Author: angelosa

hash/pc8801_flop.xml

@@ -165,7 +165,7 @@ Are the following undumped or mistranslated (check also if available in TOSEC)?
  - ザイオン (198506xx) by Victor Music Industry
  - パックマン SR版 (198506xx) by Dempa [4th ghost is orange here instead of green as in 1983 version]
  - 探検隊 (198410xx) by Data West
- - 探検隊2 〜 魔境アマゾンの奥地に黄金伝説を見た (198506xx) by Data West
+ - 探検隊2 〜 魔境アマゾンの奥地に黄金伝説を見た！ (198506xx) by Data West (available in smc777.xml)
  - またろう君 (198505xx) by Colpax
  - 労働狂 (198505xx) by FreePort
  - 今日子PARTⅠ (198505xx) by Softhouse Carroll