fix(configs): AM68x: Remove PCIe Endpoint and Backplane Documentation

The SK-AM68 EVM does not have PCIe card slots, therefore PCIe Endpoint
and Backplane functionality cannot be used on this platform.

Signed-off-by: Aksh Garg <a-garg7@ti.com>

Author: AkshGarg-19

configs/AM68/AM68_linux_toc.txt

@@ -65,8 +65,6 @@ linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-EST
 linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-CBS
 linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-IET
 linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-TSN-Tuning
-linux/Foundational_Components/Kernel/Kernel_Drivers/PCIe/PCIe_End_Point
-linux/Foundational_Components/Kernel/Kernel_Drivers/PCIe/PCIe_Backplane
 linux/Foundational_Components/Kernel/Kernel_Drivers/PCIe/PCIe_Root_Complex
 linux/Foundational_Components/Kernel/Kernel_Drivers/PMIC/pmic_tps6594
 linux/Foundational_Components_Power_Management

configs/AM68A/AM68A_linux_toc.txt

@@ -65,8 +65,6 @@ linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-EST
 linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-CBS
 linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-IET
 linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW-TSN-Tuning
-linux/Foundational_Components/Kernel/Kernel_Drivers/PCIe/PCIe_End_Point
-linux/Foundational_Components/Kernel/Kernel_Drivers/PCIe/PCIe_Backplane
 linux/Foundational_Components/Kernel/Kernel_Drivers/PCIe/PCIe_Root_Complex
 linux/Foundational_Components/Kernel/Kernel_Drivers/PMIC/pmic_tps6594
 linux/Foundational_Components_Power_Management