mb/google/eve: Set DSP SPI clock to 12MHz

To enable faster download of hotword data set the SPI clock to the
Realtek 5514 DSP chip to 12MHz instead of the default 1MHz.

BUG=b:67763576, b:66161281
TEST=cras_test_client --listen /tmp/rec.raw, trigger hotword, and check
the samples using hexdump or cras_test_client --playback_f /tmp/rec.raw

Change-Id: I92710eae25613a8202c63888b86a269803c40fe6
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Original-Signed-off-by: Cheng-Yi Chiang <cychiang@chromium.org>
Original-Change-Id: I7e50d755a90d739b6dec155228351c3974b2f3b9
Original-Reviewed-on: https://chromium-review.googlesource.com/686675
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Chinyue Chen <chinyue@chromium.org>
Original-Reviewed-by: Duncan Laurie <dlaurie@google.com>
Original-Tested-by: Chinyue Chen <chinyue@chromium.org>
Original-Commit-Queue: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/22450
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/eve/devicetree.cb

@@ -342,6 +342,7 @@ chip soc/intel/skylake
 				register "hid" = "ACPI_DT_NAMESPACE_HID"
 				register "compat_string" = ""realtek,rt5514""
 				register "irq" = "ACPI_IRQ_EDGE_HIGH(GPP_F10_IRQ)"
+				register "speed" = "12 * MHz"
 				device spi 0 on end
 			end
 		end # GSPI #0