soc: mcxa156: update systick clock frequency to 96MHz

MCXA156 max frequeny is 96MHz

Signed-off-by: Neil Chen <cheng.chen_1@nxp.com>

Author: NeilChen93

soc/nxp/mcx/mcxa/Kconfig.defconfig

@@ -9,7 +9,7 @@ config NUM_IRQS
 config SYS_CLOCK_HW_CYCLES_PER_SEC
 	default 1000000 if MCUX_OS_TIMER
 	default 16000 if MCUX_LPTMR_TIMER
-	default 150000000 if CORTEX_M_SYSTICK
+	default 96000000 if CORTEX_M_SYSTICK
 
 # Set to the minimal size of data which can be written.
 config FLASH_FILL_BUFFER_SIZE