Merge pull request #372 from duff2013/master

undocumented SNVS regs

teensy4/imxrt.h

 #define SNVS_HPLR			(IMXRT_SNVS.offset000)
 #define SNVS_HPCOMR			(IMXRT_SNVS.offset004)
 #define SNVS_HPCR			(IMXRT_SNVS.offset008)
+#define SNVS_HPSICR         (IMXRT_SNVS.offset00C)
+#define SNVS_HPSVCR         (IMXRT_SNVS.offset010)
 #define SNVS_HPSR			(IMXRT_SNVS.offset014)
-#define SNVS_HPRTCMR			(IMXRT_SNVS.offset024)
-#define SNVS_HPRTCLR			(IMXRT_SNVS.offset028)
+#define SNVS_HPSVSR         (IMXRT_SNVS.offset018)
+#define SNVS_HPHACIVR       (IMXRT_SNVS.offset01C)
+#define SNVS_HPHACR         (IMXRT_SNVS.offset020)
+#define SNVS_HPRTCMR		(IMXRT_SNVS.offset024)
+#define SNVS_HPRTCLR		(IMXRT_SNVS.offset028)
 #define SNVS_HPTAMR			(IMXRT_SNVS.offset02C)
 #define SNVS_HPTALR			(IMXRT_SNVS.offset030)
 #define SNVS_LPLR			(IMXRT_SNVS.offset034)
 #define SNVS_LPCR			(IMXRT_SNVS.offset038)
+#define SNVS_LPMKCR         (IMXRT_SNVS.offset03C)
+#define SNVS_LPSVCR         (IMXRT_SNVS.offset040)
+#define SNVS_LPTDCR         (IMXRT_SNVS.offset048)
 #define SNVS_LPSR			(IMXRT_SNVS.offset04C)
-#define SNVS_LPSRTCMR			(IMXRT_SNVS.offset050)
-#define SNVS_LPSRTCLR			(IMXRT_SNVS.offset054)
+#define SNVS_LPSRTCMR		(IMXRT_SNVS.offset050)
+#define SNVS_LPSRTCLR		(IMXRT_SNVS.offset054)
 #define SNVS_LPTAR			(IMXRT_SNVS.offset058)
-#define SNVS_LPSMCMR			(IMXRT_SNVS.offset05C)
-#define SNVS_LPSMCLR			(IMXRT_SNVS.offset060)
+#define SNVS_LPSMCMR		(IMXRT_SNVS.offset05C)
+#define SNVS_LPSMCLR		(IMXRT_SNVS.offset060)
+#define SNVS_LPPGDR         (IMXRT_SNVS.offset064)
 #define SNVS_LPGPR			(IMXRT_SNVS.offset068)
-#define IMXRT_SNVS_b		(*(IMXRT_REGISTER32_t *)0x400D4800)
+#define IMXRT_SNVS_b	(*(IMXRT_REGISTER32_t *)0x400D4800)
 #define SNVS_HPVIDR1			(IMXRT_SNVS_b.offset3F8)
 #define SNVS_HPVIDR2			(IMXRT_SNVS_b.offset3FC)
 #define SNVS_DEFAULT_PGD_VALUE		(0x41736166U)