tpm: Remove use of build-time TPM versions

There is only one place in the code which assumes at build-time that we
are using either a v1 or a v2 TPM. Fix this up and add a new function to
return the version of a TPM.

Supported TPM versions (v1 and v2) can be enabled independently and it is
possible to use both versions at once. This is useful for sandbox when
running tests.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/tpm-common.c b/lib/tpm-common.c
index 6afe59b..2bf0b41 100644
--- a/lib/tpm-common.c
+++ b/lib/tpm-common.c
@@ -12,6 +12,13 @@
 #include <tpm-common.h>
 #include "tpm-utils.h"
 
+enum tpm_version tpm_get_version(struct udevice *dev)
+{
+	struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
+
+	return priv->version;
+}
+
 int pack_byte_string(u8 *str, size_t size, const char *format, ...)
 {
 	va_list args;