arm: k3: fix fdt_del_node_path implicit declaration and a missing include

Fix missing declaration of fdt_del_node_path() while compiling am625_fdt.c and
missing common_fdt.h include in common_fdt.c

Fixes: 70aa5a94d451 ("arm: mach-k3: am62: Fixup CPU core, gpu and pru nodes in fdt")
Signed-off-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
diff --git a/arch/arm/mach-k3/common_fdt.h b/arch/arm/mach-k3/common_fdt.h
index 46c3dc5..4d23ae6 100644
--- a/arch/arm/mach-k3/common_fdt.h
+++ b/arch/arm/mach-k3/common_fdt.h
@@ -7,5 +7,6 @@
 #define _COMMON_FDT_H
 
 int fdt_fixup_msmc_ram_k3(void *blob);
+int fdt_del_node_path(void *blob, const char *path);
 
 #endif /* _COMMON_FDT_H */