spi_format() bug on KL43Z/KL27Z

### Description
- Type: Bug 
- Priority:  Major

---
## Bug

`void spi_format(spi_t *obj, int bits, int mode, int slave)` in spi_api.c always fails due to an incorrect check on `bits` arg.

`if ((bits != 8) || (bits != 16)) 
{
    error("Only 8bits and 16bits SPI supported");
    return;
}`

evaluates to true whatever the value of `bits` is.

**Target**
 KL43Z KL27Z
