Fix .file marker in irq_cm0.S

Author: bulislaw

rtos/rtx2/TARGET_CORTEX_M/TARGET_M0P/TOOLCHAIN_GCC/irq_cm0.S

@@ -24,7 +24,7 @@
  */
 
 
-        .file    "irq_cm0.s"
+        .file    "irq_cm0.S"
         .syntax  unified
 
         .equ     I_T_RUN_OFS, 28        // osRtxInfo.thread.run offset