platform: Remove string functions from tinyfdt.c

There are couple of string function defined in platform
code. We no longer need them as we can directly link minimal
libc.

Every platform required to inclde this as PLIC driver required
libc functions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>

platform/common/irqchip/plic.c

@@ -10,6 +10,7 @@
 #include <sbi/riscv_io.h>
 #include <plat/tinyfdt.h>
 #include <plat/irqchip/plic.h>
+#include <string.h>
 
 #define PLIC_PRIORITY_BASE		0x0
 #define PLIC_PENDING_BASE		0x1000
@@ -53,7 +54,7 @@ static void plic_fdt_fixup_prop(const struct fdt_node *node,
 
 	if (!prop)
 		return;
-	if (fdt_strcmp(prop->name, "interrupts-extended"))
+	if (strcmp(prop->name, "interrupts-extended"))
 		return;
 
 	cells = prop->value;