mb/intel/adlrvp: Enable PCIE RP11 for optane

A regular M.2 NVMe SSD shows up on RP9 and runs at x4 width.

Optane memory module shows up as 2 NVMe devices in x2 config:
- NVMe storage device uses RP9
- NVMe Optane memory uses RP11

Note: These two devices are sharing CLK PINs because of same M.2 slot.

TEST=Build and boot ADL RVP board using Intel Optane card.

Change-Id: Ia21d7d2fd07c4fb32291af7bb5a2e41e40316278
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46419
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/mainboard/intel/adlrvp/variants/adlrvp_p/devicetree.cb

@@ -59,6 +59,9 @@ chip soc/intel/alderlake
 	register "PcieClkSrcUsage[1]" = "0x8"
 	register "PcieRpClkReqDetect[8]" = "1"
 
+	# Enable PCH PCIE RP 11 for optane
+	register "PcieRpEnable[10]" = "1"
+
 	# Enable CPU PCIE RP 1 using PEG CLK 0
 	register "PcieClkSrcUsage[0]" = "0x40"
 
@@ -241,7 +244,7 @@ chip soc/intel/alderlake
 		device pci 1c.7 off end # RP8
 		device pci 1d.0 on  end # RP9
 		device pci 1d.1 off end # RP10
-		device pci 1d.2 off end # RP11
+		device pci 1d.2 on  end # RP11
 		device pci 1d.3 off end # RP12
 		device pci 1e.0 on  end # UART0
 		device pci 1e.1 off end # UART1