Does Ripple has support for HD wallets? I know Bitcoin supports HD wallets. In simple terms, child keys are generated for the private and public keys. And the child key can be used to restore a wallet.

I was wondering whether this kind of mechanism is available for XRP?

Or is that only specific to Bitcoin? 

If XRP has HD wallet support, which wallets provide that feature?
HD wallets are coin agnostic. The BIP32 and 49 systems simply dictate how the key derivations from a root key work. Once any particular private key is generated, it functions the same way as a non-HD key.

Thus, you can technically use an HD wallet system for ripple. However, since Ripple addresses require a minimum funding of 20 XRP, which is permanently locked in that address, wallets will usually make you use only 1 address so that you aren't forced to burn 20 XRP each time you make a transaction.