spl: crypto: fix including SHA* object files in SPL

If one of SHA* algorithms is disabled in u-boot, its code is not
included in SPL even if a given SHA* option is enabled in SPL. Fix
this.

Fixes: 603d15a572d ("spl: cypto: Bring back SPL_ versions of SHA")
Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@foundries.io>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/lib/Makefile b/lib/Makefile
index 8d8ccc8..9fa5735 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -72,9 +72,9 @@
 obj-$(CONFIG_$(SPL_)RSA) += rsa/
 obj-$(CONFIG_HASH) += hash-checksum.o
 obj-$(CONFIG_BLAKE2) += blake2/blake2b.o
-obj-$(CONFIG_SHA1) += sha1.o
-obj-$(CONFIG_SHA256) += sha256.o
-obj-$(CONFIG_SHA512) += sha512.o
+obj-$(CONFIG_$(SPL_)SHA1) += sha1.o
+obj-$(CONFIG_$(SPL_)SHA256) += sha256.o
+obj-$(CONFIG_$(SPL_)SHA512) += sha512.o
 obj-$(CONFIG_CRYPT_PW) += crypt/
 obj-$(CONFIG_$(SPL_)ASN1_DECODER) += asn1_decoder.o