[RZ_A1H]Fix some bugs about I2C, SPI, Interruptin and add terminal definition of user button.

Hi,

We fix some bugs as below.

I2C
I2C driver was not considered about 1Byte/2Byte transfer.
Add 1Byte/2Byte transfer processing in I2C driver. 

SPI
Initialize setting of SPI clock value is not correct.
Modify the value as below.
　uint16_t mask = 0x000c0; ->
　uint16_t mask = 0x000c;

InterruptIn
Fixed bugs of IRQ Edge Interrupt as below.
- Not call a function that was registered in rise, always call a function that was registered in the fall.
- If there are multiple interrupt sources, there is a possibility that end the wrong interrupt processing.

Terminal definition
Add definition of User button(SW0 and SW1) for users.

Regards,
Hamanaka