stand/uboot: Remove -fPIC here

When needed, -fPIC is added in defs.mk. While not in main, mips on
stable/13 can't tolerate it. Remove it here.

MFC After:		now (it's a build issue)
Sponsored by:		Netflix

stand/uboot/Makefile

@@ -62,8 +62,6 @@ SRCS+=	metadata.c
 
 .include "${BOOTSRC}/fdt.mk"
 
-CFLAGS+=	-fPIC
-
 # Pick up the bootstrap header for some interface items
 CFLAGS+=	-I${LDRSRC}