Revise comment of MIE.MEIE

[vicLin8712]

Issue

The current comment incorrectly suggested that CLINT timer is controlled by MIE.MEIE.

Refer to RISC-V Privileged Spec, section 3.1 "Machine-Level CSRs v1.13" (p.43), the CLINT timer interrupt is controlled by MIE.MTIE (bit 7), while MIE.MEIE (bit 11) is for external interrupts.

Fix

Updated the comment to clarify that MIE.MEIE enables external interrupts (e.g., UART).

[visitorckw]

We don't use a file name prefix in the subject line; otherwise LGTM.

[vicLin8712]

Fixed the subject line as requested.👍

[jserv]

Thank @vicLin8712 for contributing!

[visitorckw]

When looking at the git log today, I noticed that this PR's commit only contains a one-line subject title.
IMHO, the PR description does a good job explaining why the previous implementation was incorrect, but unfortunately, that context is missing from the git commit message itself.
For future reference, I’d prefer if this kind of reasoning could also be included in the git commit message, so it's preserved in the changelog.