google/reef: 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:58356
BRANCH=None
TEST=while audio playback via headset, remove headset.
Audio will be switched playback to speaker. Observe if
pop sound comes from speaker.

Change-Id: I7ad68caa88d7b3ff52ac1379fe6564de27d97777
Signed-off-by: Sathyanarayana Nujella <sathyanarayana.nujella@intel.com>
Reviewed-on: https://review.coreboot.org/16933
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

src/mainboard/google/reef/variants/baseboard/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