mfd: tps6594-spi: Add TI TPS65224 PMIC SPI

Add support for TPS65224 PMIC in TPS6594's SPI driver which has
significant functional overlap.

Signed-off-by: Bhargav Raviprakash <bhargav.r@ltts.com>
Acked-by: Julien Panis <jpanis@baylibre.com>
Link: https://lore.kernel.org/r/0109018f2fdc6328-6d13785c-9832-471b-bdfe-fb1dac3bdc60-000000@ap-south-1.amazonses.com
Signed-off-by: Lee Jones <lee@kernel.org>