sys_game_board_storage_read(): Add more known code & Improve byte casting

[brian218]

Added one more known code (0xC0), whose expected data is exactly the same as 0xF0's.
Also improved the conversion from u64[2] to u8[16];

[Nekotekina]

memcpy is honestly fine, I'm pretty sure that casting to u8[16] is UB (should cast to u8* instead)

[brian218]

memcpy is honestly fine, I'm pretty sure that casting to u8[16] is UB (should cast to u8* instead)

@Nekotekina Would reinterpret_cast<u8*>(psid) be better?

[Nekotekina]

Okay.