NFC: update bindings to not require populating dummy values

NFC GPCLK and PMIC clk sources required different configuration variables.
Only one set of variables should be included since the other isn't read.

Change-Id: Id4f5f9916bb970a87174afa49aae397e0714ffb4
Signed-off-by: Houston Hoffman <hhoffman@codeaurora.org>