[openwrt/openwrt] uml: remove left-overs from previous kernel bumps

[LEDE Commits]

chunkeey pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/62adc4bcbb1ba3e0df355341688bc2e1a764d1df

commit 62adc4bcbb1ba3e0df355341688bc2e1a764d1df
Author: Christian Lamparter <chunkeey at gmail.com>
AuthorDate: Sat Apr 26 12:05:11 2025 +0200

    uml: remove left-overs from previous kernel bumps
    
    This should have been fixed by an upstream patch in 5.12
    |commit ed102bf2afed226703eaf85a704755bdbea34583
    |Author: Randy Dunlap <rdunlap at infradead.org>
    |Date:   Thu Apr 15 10:13:52 2021 -0700
    |
    |    um: Fix W=1 missing-include-dirs warnings
    |
    |    Currently when using "W=1" with UML builds, there are over 700 warnings
    |    cc1: warning: ./arch/um/include/uapi: No such file or directory [-Wmissing-include-dirs]
    |
    |    but arch/um/ does not have include/uapi/ at all, so add that
    |    subdir and put one Kbuild file into it (since git does not track
    |    empty subdirs).
    
    Signed-off-by: Christian Lamparter <chunkeey at gmail.com>
---
 target/linux/uml/files/arch/um/include/uapi/asm/Kbuild | 0
 1 file changed, 0 insertions(+), 0 deletions(-)

diff --git a/target/linux/uml/files/arch/um/include/uapi/asm/Kbuild b/target/linux/uml/files/arch/um/include/uapi/asm/Kbuild
deleted file mode 100644
index e69de29bb2..0000000000