google/cyan: Remove support for pre-EVT board

Cleaning up code to remove support for pre-EVT rev of cyan board.

Analogous to what was done for intel/strago in commit 103f00d.

Change-Id: I29b32da8064e0743cc9c5df02ce7d3441459ee8f
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/21123
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/mainboard/google/cyan/smihandler.c

@@ -152,13 +152,6 @@ void mainboard_smi_sleep(uint8_t slp_typ)
 	/* Clear pending events that may trigger immediate wake */
 	while (google_chromeec_get_event() != 0)
 		;
-
-        if (smm_get_gnvs()->bdid == BOARD_PRE_EVT) {
-                /* Set LPC lines to low power in S3/S5. */
-                if ((slp_typ == ACPI_S3) || (slp_typ == ACPI_S5))
-                        lpc_set_low_power();
-        }
-
 #endif
 }