arm64: defconfig: Enable Redpine 91X wlan driver

The Librem 5 and it's devkit have it connected via SDIO.

Signed-off-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Author: agx

arch/arm64/configs/defconfig

@@ -409,6 +409,7 @@ CONFIG_MWIFIEX=m
 CONFIG_MWIFIEX_SDIO=m
 CONFIG_MWIFIEX_PCIE=m
 CONFIG_MT7921E=m
+CONFIG_RSI_91X=m
 CONFIG_WL18XX=m
 CONFIG_WLCORE_SDIO=m
 CONFIG_WWAN=m