spi: sifive: Remove spi_master_put in sifive_spi_remove()

The call to spi_master_put() in sifive_spi_remove() is redundant since
the master is registered using devm_spi_register_master() and no
reference hold by using spi_master_get() in sifive_spi_remove().

This is detected by Coccinelle semantic patch.

Fixes: 484a9a68 ("spi: sifive: Add driver for the SiFive SPI controller")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>