Increase CONFIG_NR_CPUS

[asahilina]

In muvm we use the pcore count as the CPU count. On M1/M2 Max that's already 8, and on the Ultra variants it becomes 16. Meanwhile M3 and M4 Max have up to 12 pcores, and the hypothetical Ultra variants 24. M4 Pro also has 10 pcores.

So CONFIG_NR_CPUS=8 is insufficient for 5 different chips already on the market (2 of which Asahi Linux already supports). We need at least 16, but most likely 24 for the almost-certain-to-come M4 Ultra. If the rumored quad chip monster device finally materializes, then we'd need up to 48.

[slp]

We always knew this need would arise sooner than later. Since we can easily produce new libkrunfw releases, I'd like to play it conservative and bump it first to 16, and then bump it further when the new chips hit the market. WDYT?

[asahilina]

Sounds good to me!