version: Move version_string[] from version.h to version_string.h

More C files do not use compile time timestamp macros and do not have to be
recompiled every time when SOURCE_DATE_EPOCH changes.

This patch moves version_string[] from version.h to version_string.h and
updates other C files which only needs version_string[] string to include
version_string.h instead of version.h. After applying this patch these
files are not recompiled every time when SOURCE_DATE_EPOCH changes.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index 578b69e..7bacf9c 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -14,7 +14,7 @@
 #include <efi_tcg2.h>
 #include <log.h>
 #include <malloc.h>
-#include <version.h>
+#include <version_string.h>
 #include <tpm-v2.h>
 #include <u-boot/hash-checksum.h>
 #include <u-boot/sha1.h>