xtensa: Add xtensa-amd_acp_7_0_adsp_zephyr-elf

This adds the config and overlay files to enable building the
toolchain needed for the acp7_0 board in Zephyr.

Signed-off-by: Sivasubramanian <[email protected]>

Author: Sivasubramanian678

.gitmodules

@@ -9,7 +9,7 @@
 	url = https://github.com/zephyrproject-rtos/newlib-cygwin.git
 [submodule "gcc"]
 	path = gcc
-	url = https://github.com/zephyrproject-rtos/gcc.git
+	url = https://github.com/Sivasubramanian678/gcc.git
 [submodule "gdb"]
 	path = gdb
 	url = https://github.com/zephyrproject-rtos/binutils-gdb.git