ARM: 8097/1: unistd.h: relocate comments back to place

Commit cb8db5d4 (UAPI: (Scripted) Disintegrate arch/arm/include/asm) moved
these syscall comments out of their context into the UAPI headers. Fix this.

Fixes: cb8db5d4 ("UAPI: (Scripted) Disintegrate arch/arm/include/asm")

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>