cris: re-use helpers to dump data in hex format

There are native helpers such as print_hex_byte() and %*ph specifier to dump
data in hex format. Re-use them instead of a custom approach.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jesper Nilsson <jespern@axis.com>