Add FLASHMEM to begin()

WireIMXRT.cpp

 
 #define PINCONFIG (IOMUXC_PAD_ODE | IOMUXC_PAD_SRE | IOMUXC_PAD_DSE(4) | IOMUXC_PAD_SPEED(1) | IOMUXC_PAD_PKE | IOMUXC_PAD_PUE | IOMUXC_PAD_PUS(3))
 
-void TwoWire::begin(void)
+FLASHMEM void TwoWire::begin(void)
 {
 	// use 24 MHz clock
 	CCM_CSCDR2 = (CCM_CSCDR2 & ~CCM_CSCDR2_LPI2C_CLK_PODF(63)) | CCM_CSCDR2_LPI2C_CLK_SEL;