soc/amd/picasso/acpi: Include platform.asl

Include platform.asl to link acpi methods for _INI, _WAK, and _PTS to
correctly enable backlight in OS for zork.

BUG=b:158087989
BRANCH=Zork
TEST=check backlight during reboot and suspend

Signed-off-by: Josie Nordrum <JosieNordrum@google.com>
Change-Id: I702f807a5907d85d083295cf339ba9d31b246627
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46670
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/amd/picasso/acpi/sb_pci0_fch.asl

@@ -22,6 +22,7 @@ Method(_OSC,4)
 
 /* 0:14.3 - LPC */
 #include <soc/amd/common/acpi/lpc.asl>
+#include <soc/amd/common/acpi/platform.asl>
 
 Name(CRES, ResourceTemplate() {
 	/* Set the Bus number and Secondary Bus number for the PCI0 device