drivers: microchip_pit: fix the path of "dt_driver.h" included

change "#include <dt_driver.h>" to "#include <kernel/dt_driver.h>" due to
"dt_driver.h" is located at "core/include/kernel/" and the path is not in
the include pathes which would cause compile errors.

Signed-off-by: Tony Han <[email protected]>

core/drivers/microchip_pit.c

@@ -6,7 +6,7 @@
 #include <assert.h>
 #include <drivers/clk.h>
 #include <drivers/clk_dt.h>
-#include <dt_driver.h>
+#include <kernel/dt_driver.h>
 #include <string.h>
 
 #define MCHP_PIT64B_FREQ		UL(5000000)	/* 5 MHz */