ARM: shmobile: r8a7791: Rename VSP1_SY clocks to VSP1_S

The r8a7791 has three VSP1 instances, one of them being named VSPS (which
stands for "VSP Standard"). The clock section in the SoC datasheet
misunderstood the abbreviation as meaning VSP System, and named the
corresponding clock VSP1(SY). This mistake has been carried over to the
kernel code.

Fix this by renaming the VSP1_SY clock to VSP1_S.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>