tpm: return false from tpm_amd_is_rng_defective on non-x86 platforms

tpm_amd_is_rng_defective is for dealing with an issue related to the
AMD firmware TPM, so on non-x86 architectures just have it inline and
return false.

Cc: [e-mail] # v6.3+
Reported-by: Sachin Sant <[e-mail]>
Reported-by: Aneesh Kumar K. V <[e-mail]>
Closes: https://lore.kernel.org/lkml/[e-mail]/
Fixes: f1324bbc4011 ("tpm: disable hwrng for fTPM on some AMD designs")
Signed-off-by: Jerry Snitselaar <[e-mail]>
Reviewed-by: Jarkko Sakkinen <[e-mail]>
Signed-off-by: Jarkko Sakkinen <[e-mail]>

drivers/char/tpm/tpm-chip.c

···
  * 6.x.y.z series: 6.0.18.6 +
  * 3.x.y.z series: 3.57.y.5 +
  */
+#ifdef CONFIG_X86
 static bool tpm_amd_is_rng_defective(struct tpm_chip *chip)
 {
 	u32 val1, val2;
···
 
 	return true;
 }
+#else
+static inline bool tpm_amd_is_rng_defective(struct tpm_chip *chip)
+{
+	return false;
+}
+#endif /* CONFIG_X86 */
 
 static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 {