soc: st: stm32: stm32n6x: Add linker section for Ethernet configuration

- Added a new section in the linker script for Ethernet configuration.
- Configured Rx and Tx descriptor sections and Ethernet buffer sections.
- Used DT_NODE_HAS_STATUS to check the status of axisram2
  and axisram1 nodes.
- Ensured proper memory allocation for Ethernet descriptors and buffers.

Signed-off-by: IBEN EL HADJ MESSAOUD Marwa <[email protected]>

Author: marwaiehm-st

soc/st/stm32/stm32n6x/section.ld

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#if DT_NODE_HAS_STATUS_OKAY(DT_NODELABEL(mac))
+
+#if DT_NODE_HAS_STATUS_OKAY(DT_NODELABEL(axisram2))
+#define sram_eth_node	DT_NODELABEL(axisram2)
+#else
+#define sram_eth_node	DT_NODELABEL(axisram1)
+#endif
+
+#if DT_NODE_HAS_STATUS_OKAY(sram_eth_node)
+SECTION_DATA_PROLOGUE(eth_stm32,(NOLOAD),)
+{
+     . = ABSOLUTE(DT_REG_ADDR(sram_eth_node));
+    *(.RxDecripSection)
+    . = ABSOLUTE(DT_REG_ADDR(sram_eth_node) + 0xC0);
+    *(.TxDecripSection)
+    . = ABSOLUTE(DT_REG_ADDR(sram_eth_node) + 0x4000);
+    *(.eth_stm32_buf)
+} GROUP_DATA_LINK_IN(LINKER_DT_NODE_REGION_NAME(sram_eth_node), LINKER_DT_NODE_REGION_NAME(sram_eth_node))
+#endif
+
+#endif /* DT_NODE_HAS_STATUS(DT_NODELABEL(mac), okay) */