RT600: Add SDK OS Timer driver

Builds the RT600 OS Timer driver when the corresponding timer
shim driver is enabled.

Signed-off-by: Mahesh Mahadevan <[email protected]>

Author: mmahadevan108

mcux/drivers/imxrt6xx/CMakeLists.txt

@@ -20,3 +20,4 @@ zephyr_sources_ifdef(CONFIG_GPIO_MCUX_LPC     fsl_gpio.c fsl_pint.c fsl_inputmux
 zephyr_sources_ifdef(CONFIG_DMA_MCUX_LPC      fsl_dma.c)
 zephyr_sources_ifdef(CONFIG_MCUX_ACMP         fsl_acmp.c)
 zephyr_sources_ifdef(CONFIG_MEMC_MCUX_FLEXSPI	fsl_flexspi.c)
+zephyr_sources_ifdef(CONFIG_MCUX_OS_TIMER	fsl_ostimer.c)