arm/xilinx-zynqmp-rpu: Simplify startup

There is no need to copy sections since the linker command file has no separate
runtime and load regions for the sections.

bsps/arm/xilinx-zynqmp-rpu/start/bspstarthooks.c

@@ -72,7 +72,6 @@ BSP_START_TEXT_SECTION void bsp_start_hook_0(void)
 
 BSP_START_TEXT_SECTION void bsp_start_hook_1(void)
 {
-  bsp_start_copy_sections();
   zynqmp_setup_mpu_and_cache();
   bsp_start_clear_bss();
 }