[PATCH AUTOSEL 6.18-5.10] reset: fix BIT macro reference

[Sasha Levin <sashal@kernel.org>]

From: Encrow Thorne <jyc0019@gmail.com>

[ Upstream commit f3d8b64ee46c9b4b0b82b1a4642027728bac95b8 ]

RESET_CONTROL_FLAGS_BIT_* macros use BIT(), but reset.h does not
include bits.h. This causes compilation errors when including
reset.h standalone.

Include bits.h to make reset.h self-contained.

Suggested-by: Troy Mitchell <troy.mitchell@linux.dev>
Reviewed-by: Troy Mitchell <troy.mitchell@linux.dev>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Encrow Thorne <jyc0019@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

LLM Generated explanations, may be completely bogus:

## Summary of Findings

### Bug Introduction
The bug was introduced by commit `dad35f7d2fc14` ("reset: replace
boolean parameters with flags parameter") which added the
`RESET_CONTROL_FLAGS_BIT_*` macros using `BIT()`. This was merged in
**v6.13-rc1** (October 2024).

### Affected Stable Trees
- **6.13.x stable**: YES - affected, needs this fix
- **6.12.x and earlier**: NO - the `RESET_CONTROL_FLAGS_BIT_*` macros
  don't exist in these trees

### Stable Kernel Criteria Assessment

| Criterion | Assessment |
|-----------|------------|
| Obviously correct? | ✅ YES - adding a missing include is trivially
correct |
| Fixes real bug? | ✅ YES - compilation error when including reset.h
standalone |
| Important issue? | ✅ YES - build failures are hard blockers |
| Small and contained? | ✅ YES - 1 line change |
| No new features? | ✅ YES - only fixes missing dependency |
| Low risk? | ✅ YES - zero runtime risk, cannot cause regressions |

### Why This Should Be Backported

1. **Build Fix Exception**: Build fixes are explicitly allowed in stable
   per `Documentation/process/stable-kernel-rules.rst` - this is an
   "include file fix" that makes the header self-contained.

2. **Zero Risk**: Adding a required include cannot cause runtime
   regressions. The `bits.h` header is universally available.

3. **Real Bug**: The compilation error is real - the header uses `BIT()`
   macro without including its definition.

4. **Reviewed by Maintainer**: Philipp Zabel (reset subsystem
   maintainer) reviewed and signed off, providing confidence in the fix.

5. **Minimal Change**: Single line addition - the smallest possible fix.

### Concerns

- No explicit `Cc: stable@vger.kernel.org` or `Fixes:` tag from
  maintainer, but this appears to be an oversight given the clear build-
  fix nature
- Only applicable to 6.13.x stable (older trees don't have the affected
  code)

### Conclusion

This is a textbook example of a stable-appropriate build fix: minimal,
zero-risk, fixes a real compilation error, and makes the header properly
self-contained. The fix should be backported to the 6.13.x stable tree
where the bug exists.

**YES**

 include/linux/reset.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/reset.h b/include/linux/reset.h
index 840d75d172f62..44f9e3415f92c 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -2,6 +2,7 @@
 #ifndef _LINUX_RESET_H_
 #define _LINUX_RESET_H_
 
+#include <linux/bits.h>
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/types.h>
-- 
2.51.0