spi: lantiq-ssc: add LTQ_ prefix to defines

The blackfin architecture has a SPI_STAT define which conflicts with
the define from the spi-lantiq-ssc driver in compile test mode. Fix
this by adding a prefix in front of every define.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Mark Brown <broonie@kernel.org>