kernel/rv1106: M5 wifi VERIFIED on c8a3 — wlan0 scan works (module build)

On-hardware proof (self-built 6.18.46, _b slot): aic8800 modules load,
download firmware, wlan0 up ([device-mac]), iw scan finds real APs
incl. SSID BlueFlare @ -43dBm. RF path fully functional. See
wifi/VERIFIED-on-c8a3.md.

Two changes from the initial built-in attempt:
- Built-in =y DEADLOCKS: aicbsp_init's eager SDIO bring-up (device_initcall,
  sequential) blocks the dw_mmc controller probe that would enumerate the
  card it waits for (aicsdio.c:597 2s down_timeout -> unregister). Converted
  to modules (=m): AIC_WLAN_SUPPORT bool->tristate; loaded late, after the
  mmc-pwrseq enumerates the card — the vendor-proven flow.
- Restored fdrv's own md5.o (each .ko needs its own MD5; bsp doesn't export
  it). Refreshed kbuild snapshot accordingly.

Kernel-size fix (CONFIG_KERNEL_GZIP -> XZ): the wifi kernel's 12.12MB gzip
zImage overran U-Boot's DTB-at-0xc00000 load boundary (Sysmem Error, FLARE-AB
fell back to _a). XZ -> 8.15MB, ~4MB headroom; also correct for a firmware
kernel. Uncompressed Image ~30MB but the ARM decompressor relocates the FDT
at runtime, so only the U-Boot load-time overlap mattered.

DRIVER-PARITY: wifi ✅ M5; BT 🔨 (module built, HCI not yet exercised).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017wB8KB3MMQztRDXCMCkPrf

kernel/rv1106-enablement/wifi/kbuild/aic8800/Kconfig

@@ -5,15 +5,22 @@
 # Ported from the vendor 5.10.160 out-of-tree source
 # (flare-edge/sdk/sysdrv/drv_ko/wifi/aic8800dc/) — see
 # warden-sdk/kernel/rv1106-enablement/wifi/PORT-PLAN.md and PORT-PROGRESS.md.
-# Built-in only (=y): the 6.18 rootfs has no working module-loading pipeline
-# yet, so these default to y rather than the vendor's default-n/tristate.
+# Modules (=m), loaded late by /oem/usr/ko/insmod_wifi.sh: the AIC8800 SDIO
+# bring-up is two-stage (bsp downloads firmware, chip re-enumerates, fdrv
+# attaches). Built-in device_initcalls run BEFORE the dw_mmc/SDIO controller
+# probes — initcalls are sequential, so aicbsp_init blocks [3.3-7.5]s while the
+# mmc controller only probes at [7.9]s afterward, and the eager bring-up
+# deadlocks (it waits for a card the blocked mmc probe hasn't enumerated).
+# Late module load, after the mmc-pwrseq enumerates the card, is the
+# vendor-proven flow. See PORT-PROGRESS.md.
 
 config AIC_WLAN_SUPPORT
-	bool "AIC wireless Support"
-	default y
+	tristate "AIC wireless Support"
+	default m
 	help
 	  This is support for the AIC wireless chip (AIC8800DC SDIO combo
-	  wifi+BT on the WardenOS 86-Panel).
+	  wifi+BT on the WardenOS 86-Panel). Build as a module (m); built-in
+	  deadlocks the two-stage SDIO bring-up (see note above).
 
 config AIC_FW_PATH
 	depends on AIC_WLAN_SUPPORT