Your build number indicates a 2015 released firmware.
The earliest firmware version I have is 2.3.3 build 130604 from the USA FTP portal of around 2015 (meaning released in 2013, just when the SE/P series was rather popular.
The earliest firmware from the European portal was 2.3.7 build 131112 (also released in 2013).
So you are asking for an earlier version (2.2.5) with a later year build date (2015). It seems confusing. Where have you seen this strange firmware version?
It came with my NVR - serial: DS-7608NI-SE/P0820151207BBRR559408284WCVU
Half briked my NVR : DS-7608NI-SE/P - Tried upgrading NVR from V2.2.5 build 150421 to V2.3.12 build 160622 (US)
Coming from a Uniview background with seamless upgrade experience I didn't realise how careful you need to be with Hikvision stuff