um: Consolidate MAGIC_SYSRQ into generic Kconfig definition

kconfiglint reports:

  K008: config MAGIC_SYSRQ has prompts in 2 separate definitions

MAGIC_SYSRQ is defined in two places with complementary conditions:

  arch/um/Kconfig:213 — depends on MCONSOLE (UML only)
  lib/Kconfig.debug:665 — depends on !UML (everything except UML)

The UML definition has existed since the initial git import in
commit 1da177e4c3f4 ("Linux-2.6.12-rc2"). UML needs MAGIC_SYSRQ to work
through its mconsole interface rather than through keyboard input, so the
UML version depends on MCONSOLE while the generic version excludes UML
entirely with `depends on !UML`.

These two definitions are logically complementary: on UML, MAGIC_SYSRQ
requires MCONSOLE; on everything else, it has no special dependencies.
This can be expressed as a single definition with
`depends on !UML || MCONSOLE`, which evaluates to:
  - On UML: requires MCONSOLE (same as before)
  - On non-UML: always satisfiable (same as before)

Consolidate into the generic definition in lib/Kconfig.debug by changing
the dependency to `depends on !UML || MCONSOLE` and merging the UML-
specific help text that explains the mconsole-based sysrq interface.
Remove the now-redundant definition from arch/um/Kconfig.

This follows the same unification pattern used by commit 7bd291abe2da
("sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig") and our earlier
SCHED_MC consolidation for SH.

No functional change — the resulting Kconfig behavior is identical.

Assisted-by: Claude:claude-opus-4-6 kconfiglint
Signed-off-by: Sasha Levin <sashal@kernel.org>
Link: https://patch.msgid.link/20260426000339.57049-1-sashal@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

0 files changed, 0 insertions, 0 deletions