mb/google/ocelot/matsu: Remove RTD3 config for SSD

The Matsu hardware design does not have a power load switch for
the SSD. Without it, the platform cannot cut off the main power rail
to the device to enter D3cold.
Therefore, remove the RTD3 chip driver and its associated GPIO
configurations (enable/reset) in the overridetree to align with the
hardware capability. The system will support D3hot instead of D3cold.

BUG=443612246
TEST=Build and boot to OS on Matsu, verify SSD still functions
    correctly and power state transitions align with HW design.

Change-Id: I84db81c17afffafbdb6c7abcc752009c824bc2ed
Signed-off-by: Ivy Jian <ivy.jian@quanta.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/91086
Reviewed-by: Pranava Y N <pranavayn@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/mainboard/google/ocelot/variants/matsu/overridetree.cb

@@ -337,13 +337,6 @@ chip soc/intel/pantherlake
 			.clk_req = 3,
 			.flags = PCIE_RP_CLK_REQ_DETECT | PCIE_RP_LTR | PCIE_RP_AER,
 			}"
-			chip soc/intel/common/block/pcie/rtd3
-				register "is_storage" = "true"
-				register "enable_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPP_H18)"
-				register "reset_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_A08)"
-				register "srcclk_pin" = "3"
-				device generic 0 on end
-			end
 		end # Gen4 M.2 SSD
 
 		device ref cnvi_wifi on