soc/intel/adl: Replace dt HeciEnabled by HECI1 disable config

Since Tiger Lake platform, the HECI1 device can be disabled on
Alder Lake platform using two different mechanism:
A. Using PMC IPC command 0xA9.
B. Sending SBI message under SMM.

In current scope of Alder Lake the default implementation is using
(B) sending sbi message under SMM. A follow up patch to add the
possible options and let platform to choose the applicable one.

List of changes:
1. Drop `HeciEnabled` from dt and dt chip configuration.
2. Replace all logic that disables HECI1 based on the `HeciEnabled`
chip config with `DISABLE_HECI1_AT_PRE_BOOT` config.
3. Default enable HECI1 device in `chipset.cb` to ensure the HECI1
device can undergo the PCI enumeration and later based on the
mainboard policy the HECI1 device can be disabled.

Mainboards that choose to make HECI1 enable during boot don't override
`DISABLE_HECI1_AT_PRE_BOOT` config.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: Ie673e634fbc0bdece419c379d417b08dfb4819e2
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60731
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/soc/intel/alderlake/chip.h

@@ -314,10 +314,6 @@ struct soc_intel_alderlake_config {
 	} IgdDvmt50PreAlloc;
 	uint8_t SkipExtGfxScan;
 
-	/* HeciEnabled decides the state of Heci1 at end of boot
-	 * Setting to 0 (default) disables Heci1 and hides the device from OS */
-	uint8_t HeciEnabled;
-
 	/* Enable/Disable EIST. 1b:Enabled, 0b:Disabled */
 	uint8_t eist_enable;