Debug profile: Change IAR profile to use -Ol instead of -On

Total Static RAM memory (data + bss): 71179(+0) bytes
Total Flash memory (text + data): 665394(-44680) bytes

Author: teetak01

tools/profiles/debug.json

@@ -53,7 +53,7 @@
     "IAR": {
         "common": [
             "--no_wrap_diagnostics",  "-e",
-            "--diag_suppress=Pa050,Pa084,Pa093,Pa082,Pe540", "-On", "-r", "-DMBED_DEBUG",
+            "--diag_suppress=Pa050,Pa084,Pa093,Pa082,Pe540", "-Ol", "-r", "-DMBED_DEBUG",
             "-DMBED_TRAP_ERRORS_ENABLED=1", "--enable_restrict"],
         "asm": [],
         "c": ["--vla", "--diag_suppress=Pe546"],