spi: spi-mem: Create macros for DTR operation

spi: spi-mem: Create macros for DTR operation

We do have macros for defining command, address, dummy and data
cycles. We also have a .dtr flag that implies sampling the bus on both
edges, but there are currently no macros enabling it. We might make use
of such macros, so let's create:
- SPI_MEM_DTR_OP_CMD
- SPI_MEM_DTR_OP_ADDR
- SPI_MEM_DTR_OP_DUMMY
- SPI_MEM_DTR_OP_DATA_OUT
- SPI_MEM_DTR_OP_DATA_OUT

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://patch.msgid.link/20241224-winbond-6-11-rc1-quad-support-v2-19-ad218dbc406f@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>