spi: add stm32f7-spi compatible

The STM32F7 SPI peripheral is nearly identical to the STM32F4, with the
only significant differences being support for a wider range of word
sizes and the addition of 32-bit transmit and receive FIFOs.

Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231102193722.3042245-4-ben.wolsieffer@hefring.com


Signed-off-by: Mark Brown <broonie@kernel.org>