ext4l: Extract alloc declarations into their own file
Create include/linux/slab.h and include/linux/vmalloc.h with memory
allocation functions:
slab.h:
- GFP flags (GFP_KERNEL, GFP_ATOMIC, etc.)
- kmalloc(), kzalloc(), kcalloc(), kmalloc_array()
- kfree(), krealloc(), kmemdup()
- kmem_cache_* functions
vmalloc.h:
- vmalloc(), vzalloc(), vfree()
- __vmalloc()
Update compat.h to include these headers and remove duplicate
definitions.
Co-developed-by: Claude Opus 4.5 <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
43f6682069