T4 Pin configuration.

There have been some issues with SCK pins and the like not appearing to work as well as on T3.x...

We have been experiementing with changing the DSE and SPEED value and this has helped in some cases.

SPI.cpp

 	CCM_CBCMR = (CCM_CBCMR & ~(CCM_CBCMR_LPSPI_PODF_MASK | CCM_CBCMR_LPSPI_CLK_SEL_MASK)) |
 		CCM_CBCMR_LPSPI_PODF(6) | CCM_CBCMR_LPSPI_CLK_SEL(2); // pg 714
 
-	uint32_t fastio = IOMUXC_PAD_SRE | IOMUXC_PAD_DSE(3) | IOMUXC_PAD_SPEED(3);
+	uint32_t fastio = IOMUXC_PAD_DSE(6) | IOMUXC_PAD_SPEED(1);
 	//uint32_t fastio = IOMUXC_PAD_DSE(3) | IOMUXC_PAD_SPEED(3);
 	//Serial.printf("SPI MISO: %d MOSI: %d, SCK: %d\n", hardware().miso_pin[miso_pin_index], hardware().mosi_pin[mosi_pin_index], hardware().sck_pin[sck_pin_index]);
 	*(portControlRegister(hardware().miso_pin[miso_pin_index])) = fastio;