spi: ti-qspi: improve ->remove() callback

there's no need to call pm_runtime_get_sync()
followed by pm_runtime_put(). We should, instead,
just call pm_runtime_put_sync() and pm_runtime_disable().

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>