Update kinetis.h

- Added bit definitions for the PIT
- limited Teensy LC to only two PITs
- added PIT_LTMR64 for Teensy LC

teensy3/kinetis.h

 #define FTM2_CONF		(*(volatile uint32_t *)0x4003A084) // Configuration
 #endif
 
-// Chapter 36: Periodic Interrupt Timer (PIT)
+// Chapter 36 (3.1)/Chapter 32 (LC): Periodic Interrupt Timer (PIT)
 #define PIT_MCR			(*(volatile uint32_t *)0x40037000) // PIT Module Control Register
+#define PIT_MCR_MDIS            (1<<1)                               // Module disable
+#define PIT_MCR_FRZ             (1<<0)                               // Freeze
+#if defined(KINETISL)
+#define PIT_LTMR64H             (*(volatile uint32_t *)0x400370E0) // PIT Upper Lifetime Timer Register
+#define PIT_LTMR64L             (*(volatile uint32_t *)0x400370E4) // PIT Lower Lifetime Timer Register
+#endif // defined(KINETISL)
 #define PIT_LDVAL0		(*(volatile uint32_t *)0x40037100) // Timer Load Value Register
 #define PIT_CVAL0		(*(volatile uint32_t *)0x40037104) // Current Timer Value Register
 #define PIT_TCTRL0		(*(volatile uint32_t *)0x40037108) // Timer Control Register
+#define PIT_TCTRL_CHN           (1<<2)                               // Chain Mode
+#define PIT_TCTRL_TIE           (1<<1)                               // Timer Interrupt Enable
+#define PIT_TCTRL_TEN           (1<<0)                               // Timer Enable
 #define PIT_TFLG0		(*(volatile uint32_t *)0x4003710C) // Timer Flag Register
+#define PIT_TFLG_TIF            (1<<0)                               // Timer Interrupt Flag (write 1 to clear)
 #define PIT_LDVAL1		(*(volatile uint32_t *)0x40037110) // Timer Load Value Register
 #define PIT_CVAL1		(*(volatile uint32_t *)0x40037114) // Current Timer Value Register
 #define PIT_TCTRL1		(*(volatile uint32_t *)0x40037118) // Timer Control Register
 #define PIT_TFLG1		(*(volatile uint32_t *)0x4003711C) // Timer Flag Register
+#if defined(KINETISK) // the 3.1 has 4 PITs, LC has only 2
 #define PIT_LDVAL2		(*(volatile uint32_t *)0x40037120) // Timer Load Value Register
 #define PIT_CVAL2		(*(volatile uint32_t *)0x40037124) // Current Timer Value Register
 #define PIT_TCTRL2		(*(volatile uint32_t *)0x40037128) // Timer Control Register
 #define PIT_CVAL3		(*(volatile uint32_t *)0x40037134) // Current Timer Value Register
 #define PIT_TCTRL3		(*(volatile uint32_t *)0x40037138) // Timer Control Register
 #define PIT_TFLG3		(*(volatile uint32_t *)0x4003713C) // Timer Flag Register
+#endif // defined(KINETISK)
 
 // Chapter 37: Low-Power Timer (LPTMR)
 #define LPTMR0_CSR		(*(volatile uint32_t *)0x40040000) // Low Power Timer Control Status Register