google/pyro: update timing of sdmode toggling

Maxim98357a speaker amp requires BCLK & SFRM to be active
and stable before it is unmuted. If there is a BLCK and no
SFRM, it results in a pop sound.

sdmode_delay property already exists which facilitates this
configuration. This patch updates "sdmode_delay" to avoid
pop sound.

BUG=chrome-os-partner:58112
BRANCH=master
TEST=emerge-pyro coreboot chromeos-bootimage
Change-Id: I5aee41957c9de7a05f962d3ede74efc6998a78fc
Signed-off-by: Kevin Chiu <Kevin.Chiu@quantatw.com>
Reviewed-on: https://review.coreboot.org/17336
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/mainboard/google/reef/variants/pyro/devicetree.cb

@@ -85,6 +85,7 @@ chip soc/intel/apollolake
 		device pci 0e.0 on	# - Audio
 			chip drivers/generic/max98357a
 				register "sdmode_gpio" =  "ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPIO_76)"
+				register "sdmode_delay" = "5"
 				device generic 0 on end
 			end
 		end