mb/novacustom/mtl-h/variants/dgpu/overridetree.cb: Fix dGPU not coming up after suspend

Fix the root port flags by bringing back the values they were at in
release v0.9.1 where suspend worked. This fixes issue where the dGPU
would not come back after suspend [1]

[1]: Dasharo/dasharo-issues#1593

Upstream-Status: Pending
Change-Id: I359527c7095fad7aaeef310d7e163a28bd0d6e45
Signed-off-by: Michał Kopeć <michal.kopec@3mdeb.com>

Author: mkopec

src/mainboard/novacustom/mtl-h/variants/dgpu/overridetree.cb

@@ -17,7 +17,7 @@ chip soc/intel/meteorlake
 			register "pcie_rp[PCH_RP(12)]" = "{
 				.clk_src = 6,
 				.clk_req = 6,
-				.flags = PCIE_RP_LTR | PCIE_RP_HOTPLUG,
+				.flags = PCIE_RP_LTR | PCIE_RP_AER | PCIE_RP_CLK_REQ_DETECT,
 			}"
 			device pci 00.0 on
 				subsystemid 0x1558 0xa761