bug in nv5x_map() function

[jrocnuck]

as of master at commit: f94dfa927190619ed70b20a548a7090a142e717f,

Line 261 of nvidiabl-models.c should be changed from reg_addr2 = bar_start + dd->reg_offset1;

to

reg_addr2 = bar_start + dd->reg_offset2;

https://github.com/guillaumezin/nvidiabl/blob/master/nvidiabl-models.c#L261