tpm: move tpm_getcap to tpm1-cmd.c

1. Move tpm_getcap to tpm1-cmd. Rename the function to tpm1_getcap.
2. Remove unused tpm_getcap_header with unused constant
as this functionality is already implemented using tpm_buf construct.

Fixes warning:
drivers/char/tpm/tpm-interface.c:452:38: warning: ‘tpm_getcap_header’ defined but not used [-Wunused-const-variable=]
 static const struct tpm_input_header tpm_getcap_header = {
                                      ^~~~~~~~~~~~~~~~~
3. Drop unused TPM_DIGEST_SIZE. It's already defined in
include/linux/tpm.h

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

drivers/char/tpm/tpm.h

@@ -541,8 +541,6 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
 			 size_t min_rsp_body_length, unsigned int flags,
 			 const char *desc);
 int tpm_startup(struct tpm_chip *chip);
-ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
-		   const char *desc, size_t min_cap_length);
 int tpm_get_timeouts(struct tpm_chip *);
 int tpm1_auto_startup(struct tpm_chip *chip);
 int tpm_do_selftest(struct tpm_chip *chip);
@@ -551,6 +549,8 @@ int tpm1_get_timeouts(struct tpm_chip *chip);
 unsigned long tpm1_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
 int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
 		    const char *log_msg);
+ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
+		    const char *desc, size_t min_cap_length);
 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
 int tpm_pm_suspend(struct device *dev);
 int tpm_pm_resume(struct device *dev);