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>

include/tpm-common.h

@@ -274,4 +274,15 @@ static inline cmd_tbl_t *get_tpm2_commands(unsigned int *size)
 }
 #endif
 
+/**
+ * tpm_get_version() - Find the version of a TPM
+ *
+ * This checks the uclass data for a TPM device and returns the version number
+ * it supports.
+ *
+ * @dev: TPM device
+ * @return version number (TPM_V1 or TPMV2)
+ */
+enum tpm_version tpm_get_version(struct udevice *dev);
+
 #endif /* __TPM_COMMON_H */