ARM: shmobile: r8a7740 legacy: Fix copied bug in comment

The corresponding bug in pm-sh7372.c was fixed in commit
70fe7b24 ("ARM: shmobile: Do not access sh7372 A4S domain
internals directly").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>