soc/intel/tigerlake: Drop redundant PcieRpEnable

The PcieRpEnable option is redundant to our on/off setting in the
devicetrees. Let's use the common coreboot infrastructure instead.

Thanks to Nicholas for doing all the mainboard legwork!

Change-Id: Iacfef5f032278919f1fcf49e31fa42bcbf1eaf20
Signed-off-by: Nico Huber <nico.h@gmx.de>
Signed-off-by: Nicholas Sudsgaard <devel+coreboot@nsudsgaard.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79920
Reviewed-by: Sean Rhodes <sean@starlabs.systems>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/volteer/variants/elemi/overridetree.cb b/src/mainboard/google/volteer/variants/elemi/overridetree.cb
index 2152ec4..4adf76a 100644
--- a/src/mainboard/google/volteer/variants/elemi/overridetree.cb
+++ b/src/mainboard/google/volteer/variants/elemi/overridetree.cb
@@ -5,8 +5,7 @@
 	register "DdiPort2Hpd" = "0"
 	register "typec_aux_bias_pads[0]" = "{.pad_auxp_dc = GPP_E10, .pad_auxn_dc = GPP_E13}"
 
-        # Enable EMMC PCIE 5 using clk 5
-        register "PcieRpEnable[4]" = "1"
+        # EMMC PCIE 5 using clk 5
         register "PcieRpLtrEnable[4]" = "1"
         register "PcieRpHotPlug[4]" = "1"
         register "PcieClkSrcUsage[5]" = "4"