spi: atmel-quadspi: Fix wrong register value written to MR

commit 162d9b5d upstream.

aq->mr should go to MR, nothing else.

Fixes: 329ca3ee ("spi: atmel-quadspi: Avoid overwriting delay register settings")
Signed-off-by: Alexander Dahl <ada@thorsis.com>
Link: https://lore.kernel.org/linux-spi/20240926-macarena-wincing-7c4995487a29@thorsis.com/T/#u
Link: https://patch.msgid.link/20240926090356.105789-1-ada@thorsis.com


Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>