ARM: dts: r8a7794: Correct hsusb parent clock

ARM: dts: r8a7794: Correct hsusb parent clock

commit dc8ee9dbdba509fb58e23ba79f2e6059fe5d8b3b upstream.

The parent clock of the HSUSB clock is the HP clock, not the MP clock.

Fixes: c7bab9f929e51761 ("ARM: shmobile: r8a7794: Add USB clocks to device tree")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>