Update azureadjoin-plan.md

Added note about TPM in FIPS mode

articles/active-directory/devices/azureadjoin-plan.md

@@ -102,7 +102,7 @@ Azure AD join:
 
 - Is only applicable to Windows 10 devices. 
 - Is not applicable to previous versions of Windows or other operating systems. If you have Windows 7/8.1 devices, you must upgrade to Windows 10 to deploy Azure AD join.
-- Is not supported on devices with TPM in FIPS mode.
+- Is supported for FIPS-compliant TPM 2.0 but not supported for TPM 1.2. If your devices have FIPS-compliant TPM 1.2, you must disable them before proceeding with Azure AD join. Microsoft does not provide any tools for disabling FIPS mode for TPMs as it is dependent on the TPM manufacturer. Please contact your hardware OEM for support.
 
 **Recommendation:** Always use the latest Windows 10 release to take advantage of updated features.