picolibc: Disable exceptions for picolibc libstdc++

Picolibc is targeted for smaller embedded systems. It brings improvement
over newlib-nano in case of pure C applications. However when used with
C++ applications all gains from smaller size of libc are wasted by
exception handling support in libstdc++.

This change disables exception support in picolibc libstdc++. It results
in decreased flash usage - ~9.5kB for ARM target.

Signed-off-by: Adrian Gielniewski <[email protected]>

Author: adigie

.gitmodules

@@ -1,6 +1,6 @@
 [submodule "crosstool-ng"]
 	path = crosstool-ng
-	url = https://github.com/zephyrproject-rtos/crosstool-ng.git
+	url = https://github.com/adigie/crosstool-ng.git
 [submodule "binutils"]
 	path = binutils
 	url = https://github.com/zephyrproject-rtos/binutils-gdb.git