spi: tle62x0: dump small buffers using %*ph

We have nice specifier in kernel for that.

It changes separator from ',' (comma) to space, though it's not a big deal
since it's just a debug message.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>