spi: bcm3835: Tidy up bcm2835_spi_reset_hw()

It doesn't need a struct spi_controller, and every callsite has
already retrieved the appropriate struct bcm2835_spi, so just pass
that directly.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/eca458ae1a0d3934d0627f90e25d294fefd4b13d.1592261248.git.robin.murphy@arm.com


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