Outdated reference to RIP-7212 precompile implementation

[rabib]

The following line incorrectly references outdated line numbers to point to the RIP-7212 precompile implementation.

specs/specs/protocol/precompiles.md

Line 34 in 7c4cb3a

[here](https://github.com/ethereum-optimism/op-geth/blob/optimism/core/vm/contracts.go#L1161-L1193).

This is because it references the tip of the optimism branch instead of a static commit.

To fix, the reference should be changed to reference a range of lines within a static commit. For example:

https://github.com/ethereum-optimism/op-geth/blob/24c89af/core/vm/contracts.go#L1519-L1535