riscv: boot: remove duplicated targets line

The "targets:" is duplicated in another line, remove the one with less
targets.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Link: https://lore.kernel.org/r/20240613153053.3835-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/boot/Makefile

@@ -18,7 +18,6 @@ OBJCOPYFLAGS_Image :=-O binary -R .note -R .note.gnu.build-id -R .comment -S
 OBJCOPYFLAGS_loader.bin :=-O binary
 OBJCOPYFLAGS_xipImage :=-O binary -R .note -R .note.gnu.build-id -R .comment -S
 
-targets := Image Image.* loader loader.o loader.lds loader.bin
 targets := Image Image.* loader loader.o loader.lds loader.bin xipImage
 
 ifeq ($(CONFIG_XIP_KERNEL),y)