Merge branch 'origin/feature/i2c'
Added spi file.
Updated header file for spi library.
Updated Uart Library for conforming to I2C
Some improvements on spi library.
Implemented spi init function for KL15.
Implemented spi read and write functions.
Added utility.h file for useful functions and definitions.
Managed spi0 pins of KL15.
Small fix on spi number control.
Small fix on spi number control. (reverse-merged from commit 3ce0f22737d4c3854746cf59f7b01c7efaff1e4c)
Restored merge error.
Merge branch 'origin/feature/uart'
Some fix on codestyle of uart module.
Fix return value on setBaudRate uart function.
Added ifdef on baudrate setting of spi.
Moved platforms ifdef inside clock function.
Fix uart register for KL15.
Fix spi register usage with Freescale define.
Fix i2c registers esage with Freescale define.