Rename CCM_CCGR1_GPT defines

Current naming is confusing since it differs between GTP1 and GTP2. The GTP2 version is compatible to the naming in the data sheet. So I suggest to adjust the naming for  GPT1

teensy4/imxrt.h

@@ -1278,8 +1278,8 @@ typedef struct {
 #define CCM_CCGR1_CSU(n)			((uint32_t)(((n) & 0x03) << 28))
 #define CCM_CCGR1_GPIO1(n)			((uint32_t)(((n) & 0x03) << 26))
 #define CCM_CCGR1_LPUART4(n)			((uint32_t)(((n) & 0x03) << 24))
-#define CCM_CCGR1_GPT_SERIAL(n)			((uint32_t)(((n) & 0x03) << 22))
-#define CCM_CCGR1_GPT(n)			((uint32_t)(((n) & 0x03) << 20))
+#define CCM_CCGR1_GPT1_SERIAL(n)			((uint32_t)(((n) & 0x03) << 22))
+#define CCM_CCGR1_GPT1_BUS(n)			((uint32_t)(((n) & 0x03) << 20))
 #define CCM_CCGR1_ADC1(n)			((uint32_t)(((n) & 0x03) << 16))
 #define CCM_CCGR1_AOI2(n)			((uint32_t)(((n) & 0x03) << 14))
 #define CCM_CCGR1_PIT(n)			((uint32_t)(((n) & 0x03) << 12))