Turn data cache on

This fixes hathach#1894.  I'm not really
sure if this is the correct way to fix it, and I have not tested on all the
rest of the family members, however, this lets the i.MX1010 work again.

The problem:  the latest SDK update does not enable the data cache by default
This causes an assert in board_init() when attemping to control clock
gating.  I haven't investigated further as to *why* it's a problem, but it
is a problem.

Author: ccrome

hw/bsp/imxrt/family.c

@@ -55,6 +55,12 @@ const uint8_t dcd_data[] = { 0x00 };
 
 void board_init(void)
 {
+  // make sure the dcache is on.
+#if defined(__DCACHE_PRESENT) && __DCACHE_PRESENT
+    if (SCB_CCR_DC_Msk != (SCB_CCR_DC_Msk & SCB->CCR))
+        SCB_EnableDCache();
+#endif
+
   // Init clock
   BOARD_BootClockRUN();
   SystemCoreClockUpdate();