refactor(core/embed): move __stack_chk_fail to a better location

[no changelog]

core/embed/lib/error_handling.c

@@ -38,6 +38,14 @@
 #define COLOR_FATAL_ERROR COLOR_BLACK
 #endif
 
+uint32_t __stack_chk_guard = 0;
+
+// Calls to this function are inserted by the compiler
+// when stack protection is enabled.
+void __attribute__((noreturn, used)) __stack_chk_fail(void) {
+  error_shutdown("(SS)");
+}
+
 void __attribute__((noreturn))
 error_shutdown_ex(const char *title, const char *message, const char *footer) {
   if (title == NULL) {

core/embed/trezorhal/stm32f4/common.c

@@ -36,12 +36,6 @@
 #include "backlight_pwm.h"
 #endif
 
-uint32_t __stack_chk_guard = 0;
-
-void __attribute__((noreturn)) __stack_chk_fail(void) {
-  error_shutdown("(SS)");
-}
-
 // reference RM0090 section 35.12.1 Figure 413
 #define USB_OTG_HS_DATA_FIFO_RAM (USB_OTG_HS_PERIPH_BASE + 0x20000U)
 #define USB_OTG_HS_DATA_FIFO_SIZE (4096U)

core/embed/trezorhal/stm32u5/common.c

@@ -32,12 +32,6 @@
 
 #include "stm32u5xx_ll_utils.h"
 
-uint32_t __stack_chk_guard = 0;
-
-void __attribute__((noreturn)) __stack_chk_fail(void) {
-  error_shutdown("(SS)");
-}
-
 void invalidate_firmware(void) {
   // on stm32u5, we need to disable the instruction cache before erasing the
   // firmware - otherwise, the write check will fail