spi: lpspi: Add include guards to common header file

Not motivated by any impacted functionality but rather following good
practices. Recursive inclusions may be confusing and hard to diagnose.

Signed-off-by: Luis Ubieda <[email protected]>

Author: ubieda

drivers/spi/spi_nxp_lpspi/spi_nxp_lpspi_priv.h

@@ -4,6 +4,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#ifndef ZEPHYR_DRIVERS_SPI_SPI_NXP_LPSPI_PRIV_H_
+#define ZEPHYR_DRIVERS_SPI_SPI_NXP_LPSPI_PRIV_H_
+
 #include <zephyr/drivers/spi.h>
 #include <zephyr/drivers/spi/rtio.h>
 #include <zephyr/drivers/pinctrl.h>
@@ -136,3 +139,5 @@ int lpspi_wait_tx_fifo_empty(const struct device *dev);
 
 #define SPI_NXP_LPSPI_HAS_DMAS(n)                                                                  \
 	UTIL_AND(DT_INST_DMAS_HAS_NAME(n, tx), DT_INST_DMAS_HAS_NAME(n, rx))
+
+#endif /* ZEPHYR_DRIVERS_SPI_SPI_NXP_LPSPI_PRIV_H_ */