spi: stm32-qspi: Remove unused qspi field of struct stm32_qspi_flash

Remove struct stm32_qspi_flash's field qspi which is not used.

Fixes: c530cd1d ("spi: spi-mem: add stm32 qspi controller")
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20210615090115.30702-1-patrice.chotard@foss.st.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-stm32-qspi.c

@@ -93,7 +93,6 @@
 #define STM32_AUTOSUSPEND_DELAY -1
 
 struct stm32_qspi_flash {
-	struct stm32_qspi *qspi;
 	u32 cs;
 	u32 presc;
 };
@@ -590,7 +589,6 @@ static int stm32_qspi_setup(struct spi_device *spi)
 	presc = DIV_ROUND_UP(qspi->clk_rate, spi->max_speed_hz) - 1;
 
 	flash = &qspi->flash[spi->chip_select];
-	flash->qspi = qspi;
 	flash->cs = spi->chip_select;
 	flash->presc = presc;