ARM: shmobile: sh73a0: fix Z and ZG clock hierarchy

Z and ZG clocks on sh73a0 have pll0 as their parent, not pll1.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>