mb/asus/p8z77-m: Ensure RAM stays powered in ACPI S3 suspend

Enable 3VSBSW# in NCT6779D super I/O like other variants in the family,
needed to maintain power to memory during S3 suspend. Without it
resuming totally fails.

(Enabling it in devicetree is OK; it needs not be done in early
board init.)

TEST=Resuming from S3 works.

Change-Id: Ia8059b2a263ab5c459e54685f046eeb913776473
Signed-off-by: Keith Hui <buurin@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78205
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Kevin Keijzer <kevin@quietlife.nl>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/asus/p8x7x-series/variants/p8z77-m/overridetree.cb

@@ -52,6 +52,7 @@ chip northbridge/intel/sandybridge
 						drq 0xe1 = 0x80		# GP07 high
 					end
 					device pnp 2e.a on		# ACPI
+						drq 0xe4 = 0x10 	# Enable 3VSBSW#, needed for S3 suspend
 						drq 0xe7 = 0x11		# HWM reset by LRESET#, 0.5s S3 delay for compatibility
 						drq 0xf2 = 0x5d		# Enable RSTOUT[0-2]# and PME
 					end