mainboard/google/kahlee: Update Grunt devicetree.

Grunt's devicetree dropped some entries when it was split from the
kahlee variant. This commit restores:
  spd_addr_lookup - memory information for AGESA
  dram_clear_on_reset - keeps DRAM contents on reset
  uma_mode - needed for vbios
  uma_size - needed for vbios

Change-Id: I1d8cdc97594867f1d706318370055087976a5104
Signed-off-by: Justin TerAvest <teravest@chromium.org>
Reviewed-on: https://review.coreboot.org/23099
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Richard Spiegel <richard.spiegel@silverbackltd.com>
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/google/kahlee/variants/grunt/devicetree.cb

@@ -13,6 +13,14 @@
 # GNU General Public License for more details.
 #
 chip soc/amd/stoneyridge
+	register "spd_addr_lookup" = "
+	{
+		{ {0xA0, 0x00} }, // socket 0 - Channel 0, slot 0
+	}"
+	register "dram_clear_on_reset" = "DRAM_CONTENTS_KEEP"
+	register "uma_mode" = "UMAMODE_SPECIFIED_SIZE"
+	register "uma_size" = "128 * MiB"
+
 	device cpu_cluster 0 on
 		device lapic 10 on end
 	end