ChromeOS: Promote variant_cros_gpio()

The only purpose of mainboard_chromeos_acpi_generate()
was to pass cros_gpio array for ACPI \\OIPG package
generation.

Promote variant_cros_gpio() from baseboards to ChromeOS
declaration.

Change-Id: I5c2ac1dcea35f1f00dea401528404bc6ca0ab53c
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58897
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/vendorcode/google/chromeos/chromeos.h

@@ -37,17 +37,10 @@ void chromeos_init_chromeos_acpi(void);
  */
 enum cb_err get_dsm_calibration_from_key(const char *key, uint64_t *value);
 
-/*
- * Create the OIPG package containing the Chrome OS gpios described by
- * the chromeos_gpio array.
- */
-struct cros_gpio;
-void chromeos_acpi_gpio_generate(const struct cros_gpio *gpios, size_t num);
-
 /*
  * Declaration for mainboards to use to generate ACPI-specific Chrome OS needs.
  */
-void mainboard_chromeos_acpi_generate(void);
+void chromeos_acpi_gpio_generate(void);
 
 enum {
 	CROS_GPIO_REC = 1, /* Recovery */
@@ -104,4 +97,6 @@ struct cros_gpio {
 #define CROS_GPIO_PE_AH(num, dev) \
 	CROS_GPIO_PE_INITIALIZER(CROS_GPIO_ACTIVE_HIGH, num, dev)
 
+const struct cros_gpio *variant_cros_gpios(size_t *num);
+
 #endif /* __CHROMEOS_H__ */