AGESA/PI: replace HUDSON_DISABLE_IMC with HUDSON_IMC_ENABLE

Only a few boards are using IMC for the onboard fan control,
so regarding the availability of IMC selection it should be opt-in,
not opt-out. Also, select HUDSON_IMC_ENABLE for Gizmo 2
because Gizmo 2 could use IMC for the onboard fan control.

Signed-off-by: Mike Banon <mikebdp2@gmail.com>
Change-Id: I3590b13c3b155405d61e373daf1bd82ca8e3bd16
Reviewed-on: https://review.coreboot.org/c/30756
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/southbridge/amd/agesa/hudson/Kconfig

@@ -55,8 +55,13 @@ config HUDSON_XHCI_FWM
 	help
 	  Add Hudson 2/3/4 XHCI Firmware to support the onboard USB 3.0
 
+config HUDSON_IMC_ENABLE
+	bool
+	default n
+
 config HUDSON_IMC_FWM
-	bool "Add imc firmware"
+	bool "Add IMC firmware"
+	depends on HUDSON_IMC_ENABLE
 	default y if USE_BLOBS
 	select SPI_FLASH_HAS_VOLATILE_GROUP if SPI_FLASH
 	help

src/southbridge/amd/pi/hudson/Kconfig

@@ -22,9 +22,6 @@ config SOUTHBRIDGE_AMD_PI_AVALON
 config SOUTHBRIDGE_AMD_PI_KERN
 	bool
 
-config HUDSON_DISABLE_IMC
-	bool
-
 if SOUTHBRIDGE_AMD_PI_AVALON || SOUTHBRIDGE_AMD_PI_BOLTON || SOUTHBRIDGE_AMD_PI_KERN
 
 config SOUTHBRIDGE_SPECIFIC_OPTIONS # dummy
@@ -58,9 +55,13 @@ config HUDSON_XHCI_FWM
 	help
 	  Add Hudson 2/3/4 XHCI Firmware to support the onboard USB 3.0
 
+config HUDSON_IMC_ENABLE
+	bool
+	default n
+
 config HUDSON_IMC_FWM
 	bool "Add IMC firmware"
-	depends on !HUDSON_DISABLE_IMC
+	depends on HUDSON_IMC_ENABLE
 	default y
 	help
 	  Add Hudson 2/3/4 IMC Firmware to support the onboard fan control