tools: b43-tools: Update to latest HEAD

Add the following changes:
```
12524df b43-asm: fix undefined behavior by using unsigned shift
fa9cb86 Merge pull request #9 from PolynomialDivision/unsinged-fix
5d592cb fwcutter: Fix compiler warning
b96318b dasm: Fix compiler warning
2270cee ssb_sprom: Fix _DEFAULT_SOURCE warning
4781cde ssb_sprom: Fix compiler warning
cce45e3 ssb_sprom: Update .gitignore
5ca416f disassembler: Update .gitignore
44673b6 Update .gitignore
0c8f8b6 assembler: Update .gitignore
1f5b63d fwcutter: Update .gitignore
35fe438 Add README.md
```

Link: openwrt/openwrt#20542
Signed-off-by: Hauke Mehrtens <[email protected]>

Author: hauke

tools/b43-tools/Makefile

@@ -8,12 +8,12 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=b43-tools
-PKG_DATE:=2025-05-04
+PKG_DATE:=2025-09-23
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/mbuesch/b43-tools.git
-PKG_SOURCE_VERSION:=cc352349153eeda9c164ecd0d06c161a59ec8753
-PKG_MIRROR_HASH:=c1feba649c2cf3e984a2b897b4a6938252515c0833358d51bd15e049b6b2fb65
+PKG_MIRROR_HASH:=421520ea1983c4774864ec47f9333e5dfa947ef759ce543830b958c63a9c5974
+PKG_SOURCE_VERSION:=35fe4385a8d738874ef004fa47c5aa40b2c08b3e
 
 include $(INCLUDE_DIR)/host-build.mk