mb/google/brya/var/redrix: Add alias back to RP6 WWAN device

This alias name is required for the mainboard.c code to generate the
appropriate power-off seqeuence for use during orderly S5 shutdown
from the OS. It had been accidentally removed, but is required, so
this patch adds it.

BUG=b:227788351
TEST=compile

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: I8936a01bd3a6b908033a8c58bd4e84b30d199e98
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63556
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/mainboard/google/brya/variants/redrix/overridetree.cb

@@ -198,7 +198,7 @@ chip soc/intel/alderlake
 				register "wake_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_A7)"
 				register "add_acpi_dma_property" = "true"
 				use rp6_rtd3 as rtd3dev
-				device generic 0 on
+				device generic 0 alias rp6_wwan on
 					probe DB_LTE LTE_PCIE
 				end
 			end