dt-bindings: phy: intel: Add Thunder Bay eMMC PHY bindings

Binding description for Intel Thunder Bay eMMC PHY.
Added the newly introduced files into MAINTAINERS file-list

Signed-off-by: Rashmi A <rashmi.a@intel.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211027115516.4475-4-rashmi.a@intel.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>