global: Rename SPL_ to XPL_

Use XPL_ as the symbol to indicate an SPL build. This means that SPL_ is
no-longer set.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 3bc34cd..34b69c1 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -11,19 +11,19 @@
 obj-$(CONFIG_CMD_GO) += boot.o
 obj-y	+= cache.o
 obj-$(CONFIG_SIFIVE_CACHE) += sifive_cache.o
-ifeq ($(CONFIG_$(SPL_)RISCV_MMODE),y)
-obj-$(CONFIG_$(SPL_)RISCV_ACLINT) += aclint_ipi.o
+ifeq ($(CONFIG_$(XPL_)RISCV_MMODE),y)
+obj-$(CONFIG_$(XPL_)RISCV_ACLINT) += aclint_ipi.o
 obj-$(CONFIG_ANDES_PLICSW) += andes_plicsw.o
 else
 obj-$(CONFIG_SBI) += sbi.o
 obj-$(CONFIG_SBI_IPI) += sbi_ipi.o
 endif
 obj-y	+= interrupts.o
-ifeq ($(CONFIG_$(SPL_)SYSRESET),)
+ifeq ($(CONFIG_$(XPL_)SYSRESET),)
 obj-y	+= reset.o
 endif
 obj-y   += setjmp.o
-obj-$(CONFIG_$(SPL_)SMP) += smp.o
+obj-$(CONFIG_$(XPL_)SMP) += smp.o
 obj-$(CONFIG_XPL_BUILD)	+= spl.o
 obj-y   += fdt_fixup.o
 obj-$(CONFIG_$(SPL)CMD_BDI) += bdinfo.o