powerpc: dts: turris1x.dts: Fix PCIe MEM size for pci2 node

Freescale PCIe controllers on their PCIe Root Ports do not have any
mappable PCI BAR allocate from PCIe MEM.

Information about 1MB window on BAR0 of PCIe Root Port was misleading
because Freescale PCIe controllers have at BAR0 position different register
PEXCSRBAR, and kernel correctly skipts BAR0 for these Freescale PCIe Root
Ports.

So update comment about P2020 PCIe Root Port and decrease PCIe MEM size
required for PCIe controller (pci2 node) on which is on-board xHCI
controller.

lspci confirms that on P2020 PCIe Root Port is no PCI BAR and /proc/iomem
sees that only c0000000-c000ffff and c0010000-c0011fff ranges are used.

Fixes: 54c15ec3 ("powerpc: dts: Add DTS file for CZ.NIC Turris 1.x routers")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230505172818.18416-1-pali@kernel.org

arch/powerpc/boot/dts/turris1x.dts

@@ -476,12 +476,12 @@ pci2: pcie@ffe08000 {
 		 * channel 1 (but only USB 2.0 subset) to USB 2.0 pins on mPCIe
 		 * slot 1 (CN5), channels 2 and 3 to connector P600.
 		 *
-		 * P2020 PCIe Root Port uses 1MB of PCIe MEM and xHCI controller
+		 * P2020 PCIe Root Port does not use PCIe MEM and xHCI controller
 		 * uses 64kB + 8kB of PCIe MEM. No PCIe IO is used or required.
-		 * So allocate 2MB of PCIe MEM for this PCIe bus.
+		 * So allocate 128kB of PCIe MEM for this PCIe bus.
 		 */
 		reg = <0 0xffe08000 0 0x1000>;
-		ranges = <0x02000000 0x0 0xc0000000 0 0xc0000000 0x0 0x00200000>, /* MEM */
+		ranges = <0x02000000 0x0 0xc0000000 0 0xc0000000 0x0 0x00020000>, /* MEM */
 			 <0x01000000 0x0 0x00000000 0 0xffc20000 0x0 0x00010000>; /* IO */
 
 		pcie@0 {