The ss pin of spi0 is the same as sck pin. According to the
visionfive 2 documentation, it should be pin 49 instead of 48.

Fixes: 74fb20c8 ("riscv: dts: starfive: Add spi node and pins configuration")
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>