drivers/intel/gma: Move IGD OpRegion to CBMEM

It never was in GNVS, it never belonged among the ACPI tables. Having
it in CBMEM, makes it easy to look the location up on resume, and saves
us additional boilerplate.

TEST=Booted Linux on Lenovo/X201s, confirmed ASLS is set and
     intel_backlight + acpi_video synchronize, both before and
     after suspend.

Change-Id: I5fdd6634e4a671a85b1df8bc9815296ff42edf29
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40724
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/intel/braswell/gfx.c b/src/soc/intel/braswell/gfx.c
index 9de5126..0365ea2 100644
--- a/src/soc/intel/braswell/gfx.c
+++ b/src/soc/intel/braswell/gfx.c
@@ -9,7 +9,6 @@
 #include <drivers/intel/gma/i915.h>
 #include <reg_script.h>
 #include <soc/gfx.h>
-#include <soc/nvs.h>
 #include <soc/pci_devs.h>
 #include <soc/ramstage.h>
 
@@ -50,6 +49,8 @@
 {
 	printk(BIOS_SPEW, "%s/%s (%s)\n", __FILE__, __func__, dev_name(dev));
 
+	intel_gma_init_igd_opregion();
+
 	if (!CONFIG(RUN_FSP_GOP)) {
 		/* Pre VBIOS Init */
 		gfx_pre_vbios_init(dev);
@@ -60,20 +61,6 @@
 		/* Post VBIOS Init */
 		gfx_post_vbios_init(dev);
 	}
-	intel_gma_restore_opregion();
-}
-
-uintptr_t gma_get_gnvs_aslb(const void *gnvs)
-{
-	const global_nvs_t *gnvs_ptr = gnvs;
-	return (uintptr_t)(gnvs_ptr ? gnvs_ptr->aslb : 0);
-}
-
-void gma_set_gnvs_aslb(void *gnvs, uintptr_t aslb)
-{
-	global_nvs_t *gnvs_ptr = gnvs;
-	if (gnvs_ptr)
-		gnvs_ptr->aslb = aslb;
 }
 
 static void gma_generate_ssdt(const struct device *dev)