vc/chromeos: Provide inline fallbacks for Chromebook Plus branding

Currently, mainboards that do not support Google TPM must manually
define stubs for chromeos_device_branded_plus_hard() and
chromeos_device_branded_plus_soft() to satisfy the linker.

Move these stubs into vendorcode/google/chromeos/chromeos.h as static
inline functions when CONFIG(TPM_GOOGLE) is disabled. This reduces
code duplication and allows the removal of redundant stub definitions
in the ptlrvp mainboard.

Change-Id: If270d4815c687a409fec7058c224f987f9e2741a
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/91474
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/intel/ptlrvp/intel.c

@@ -23,13 +23,3 @@ int get_recovery_mode_switch(void)
 {
 	return 0;
 }
-
-bool chromeos_device_branded_plus_hard(void)
-{
-	return false;
-}
-
-bool chromeos_device_branded_plus_soft(void)
-{
-	return false;
-}

src/vendorcode/google/chromeos/chromeos.h

@@ -34,6 +34,8 @@ void chromeos_set_ramoops(void *ram_oops, size_t size);
  * Return "UNDEFINED_FACTORY_CONFIG" in case of error.
  */
 uint64_t chromeos_get_factory_config(void);
+
+#if CONFIG(TPM_GOOGLE)
 /*
  * Determines whether a ChromeOS device is branded as a Chromebook-Plus
  * based on specific bit flags:
@@ -57,6 +59,18 @@ bool chromeos_device_branded_plus_hard(void);
  * To be considered a soft-branded Chromebook-Plus, both of these conditions need to be met.
  */
 bool chromeos_device_branded_plus_soft(void);
+#else
+/* Inline fallback for platforms without Google TPM */
+static inline bool chromeos_device_branded_plus_hard(void)
+{
+	return false;
+}
+
+static inline bool chromeos_device_branded_plus_soft(void)
+{
+	return false;
+}
+#endif
 
 /*
  * Declaration for mainboards to use to generate ACPI-specific ChromeOS needs.