acpid: fix common path bug (was depth-3 notation in depth-2 crate)

acpid lives at drivers/acpid/ (depth 2 in the base workspace). All
other depth-2 crates (pcid, hwd, inputd, vboxd, rtcd, thermald,
virtio-core, redoxerd) correctly use path = "../common" (1 '..') to
reach drivers/common/. acpid was the sole outlier using "../../common"
(2 '..'), which resolves to base/common/ — a path that has never
existed in this fork.

The build script's overlay-integrity auto-repair mechanism normally
papers over this (creating a transient symlink or rewriting the path
during staging). When that mechanism fails — as it did during
LG Gram Round 1 verification ("5 recipe.toml files could not be
restored") — the bug surfaces as a hard manifest-load failure:

  error: failed to load manifest for workspace member
    .../local/sources/base/drivers/acpid
    failed to load manifest for dependency 'common'
    failed to read .../local/sources/base/common/Cargo.toml
    No such file or directory (os error 2)

The fix is one character: "../../common" → "../common". This makes
acpid consistent with the 8 other depth-2 crates and removes the
dependency on the build-script overlay-repair hack.

No semantic change — same crate, same workspace membership, just a
correctly-resolving path.

drivers/acpid/Cargo.toml

@@ -23,7 +23,7 @@ ron.workspace = true
 serde.workspace = true
 
 amlserde = { path = "../amlserde" }
-common = { path = "../../common" }
+common = { path = "../common" }
 daemon = { path = "../../daemon" }
 libredox.workspace = true
 redox-scheme.workspace = true