iwlwifi: work around reverse dependency on MEI

If the iwlmei code is a loadable module, the main iwlwifi driver
cannot be built-in:

x86_64-linux-ld: drivers/net/wireless/intel/iwlwifi/pcie/trans.o: in function `iwl_pcie_prepare_card_hw':
trans.c:(.text+0x4158): undefined reference to `iwl_mei_is_connected'

Unfortunately, Kconfig enforces the opposite, forcing the MEI driver to
not be built-in if iwlwifi is a module.

To work around this, decouple iwlmei from iwlwifi and add the
dependency in the other direction.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20211207151447.3338818-1-arnd@kernel.org
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/Kconfig

@@ -2,6 +2,7 @@
 config IWLWIFI
 	tristate "Intel Wireless WiFi Next Gen AGN - Wireless-N/Advanced-N/Ultimate-N (iwlwifi) "
 	depends on PCI && HAS_IOMEM && CFG80211
+	depends on IWLMEI || !IWLMEI
 	select FW_LOADER
 	help
 	  Select to build the driver supporting the:
@@ -92,32 +93,6 @@ config IWLWIFI_BCAST_FILTERING
 	  If unsure, don't enable this option, as some programs might
 	  expect incoming broadcasts for their normal operations.
 
-config IWLMEI
-	tristate "Intel Management Engine communication over WLAN"
-	depends on INTEL_MEI
-	depends on PM
-	depends on IWLMVM
-	help
-	  Enables the iwlmei kernel module.
-
-	  CSME stands for Converged Security and Management Engine. It is a CPU
-	  on the chipset and runs a dedicated firmware. AMT (Active Management
-	  Technology) is one of the applications that run on that CPU. AMT
-	  allows to control the platform remotely.
-
-	  This kernel module allows to communicate with the Intel Management
-	  Engine over Wifi. This is supported starting from Tiger Lake
-	  platforms and has been tested on 9260 devices only.
-	  If AMT is configured not to use the wireless device, this module is
-	  harmless (and useless).
-	  Enabling this option on a platform that has a different device and
-	  has Wireless enabled on AMT can prevent WiFi from working correctly.
-
-	  For more information see
-	  <https://software.intel.com/en-us/manageability/>
-
-	  If unsure, say N.
-
 menu "Debugging Options"
 
 config IWLWIFI_DEBUG
@@ -172,3 +147,28 @@ config IWLWIFI_DEVICE_TRACING
 endmenu
 
 endif
+
+config IWLMEI
+	tristate "Intel Management Engine communication over WLAN"
+	depends on INTEL_MEI
+	depends on PM
+	help
+	  Enables the iwlmei kernel module.
+
+	  CSME stands for Converged Security and Management Engine. It is a CPU
+	  on the chipset and runs a dedicated firmware. AMT (Active Management
+	  Technology) is one of the applications that run on that CPU. AMT
+	  allows to control the platform remotely.
+
+	  This kernel module allows to communicate with the Intel Management
+	  Engine over Wifi. This is supported starting from Tiger Lake
+	  platforms and has been tested on 9260 devices only.
+	  If AMT is configured not to use the wireless device, this module is
+	  harmless (and useless).
+	  Enabling this option on a platform that has a different device and
+	  has Wireless enabled on AMT can prevent WiFi from working correctly.
+
+	  For more information see
+	  <https://software.intel.com/en-us/manageability/>
+
+	  If unsure, say N.