ARM: OMAP2+: fix a kernel-doc warning

Use the correct function name in a kernel-doc comment to prevent a
warning:

powerdomain.c:1171: warning: expecting prototype for pwrdm_save_context(). Prototype was for pwrdm_restore_context() instead

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: patches@armlinux.org.uk
Message-ID: <20240117011004.22669-12-rdunlap@infradead.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>