freertos(SMP): Fix SMP FreeRTOS portDISABLE_INTERRUPTS() macro on xtensa port

The portDISABLE_INTERRUPTS() macro on Xtensa should return only the interrupt
mask/level before the interrupts were disabled. Previously, the entire contents
of PS register were returned (i.e., direct return from RSIL instruction without
any bit masking or shifting).

This commit fixes the portDISABLE_INTERRUPTS() macro to return the INTLEVEL
bitfield of the PS register.

components/freertos/FreeRTOS-Kernel-SMP/portable/xtensa/include/freertos/portmacro.h

@@ -143,6 +143,7 @@ void vPortCleanUpTCB ( void *pxTCB );
 #define portDISABLE_INTERRUPTS()            ({ \
     unsigned int prev_level = XTOS_SET_INTLEVEL(XCHAL_EXCM_LEVEL); \
     portbenchmarkINTERRUPT_DISABLE(); \
+    prev_level = ((prev_level >> XCHAL_PS_INTLEVEL_SHIFT) & XCHAL_PS_INTLEVEL_MASK); \
     prev_level; \
 })