spi: lpspi: Replace all "master" with "controller"

[ Upstream commit 07d71557494c05b0651def1651bf6d7e7f47bbbb ]

In order to enable the slave mode and make the code more readable,
replace all related structure names and object names which is
named "master" with "controller".

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: 730bbfaf7d48 ("spi: spi-fsl-lpspi: Fix scldiv calculation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit bebc69b574d6a3c54e8951dd891e78a20e2a3f54)
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>