VideoInterface: Adjust even-field to match odd-field pacing when PSB values differ.

[jordan-woyak]

This fixes a frame pacing problem in many GC games that becomes apparent with the improvements of #13387

Super Mario Sunshine:

(VI->BeginField): Address: 004C8D80 | WPL 40 | STD 80 | EQ 6 | PRB 40 | ACV 224 | PSB 19 | Field Odd
HorizScaling: 0100 | fbwidth 640 | 8108100 | 8108100
(VI->BeginField): Address: 004C8D80 | WPL 40 | STD 80 | EQ 6 | PRB 41 | ACV 224 | PSB 18 | Field Even
HorizScaling: 0100 | fbwidth 640 | 8108100 | 8108100

Odd/Even PRB/PSB values differ and we present before PSB causing bad pacing between odd/even fields.

Before:

After:

Just a side note: these values are state-saved so comparisons cannot be done if you are loading a state. :)
Also, you really won't be able to observe a difference without #13387