mb/google/poppy/variants/rammus: Shorten oem_table_id to RAMMUS

This patch modifies "oem_table_id" from "RAMMUSMAX" to "RAMMUS"
so that the audio topology file can be loaded properly by the
operating system.

BUG=b:112945714
BRANCH=master
TEST=There is no error message like "failed to load topology firmware" in
     kernel v4.4 log.

Change-Id: I66a38ea38791dd3d9606a05b7b696236c350237f
Signed-off-by: Marx Wang <marx.wang@intel.com>
Reviewed-on: https://review.coreboot.org/28870
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/poppy/variants/rammus/nhlt.c

@@ -38,6 +38,6 @@ void variant_nhlt_oem_overrides(const char **oem_id, const char **oem_table_id,
 				uint32_t *oem_revision)
 {
 	*oem_id = "GOOGLE";
-	*oem_table_id = "RAMMUSMAX";
+	*oem_table_id = "RAMMUS";
 	*oem_revision = 0;
 }