MAINTAINERS: Add a maintainer for OCP Time Card

I've been contributing and reviewing patches for ptp_ocp driver for
some time and I'm taking care of it's github mirror. On Jakub's
suggestion, I would like to step forward and become a maintainer for
this driver. This patch adds a dedicated entry to MAINTAINERS.
Signed-off-by: Vadim Fedorenko <vadfed@fb.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/r/20220621233131.21240-1-vfedorenko@novek.ruSigned-off-by: Jakub Kicinski <kuba@kernel.org>

MAINTAINERS

@@ -14868,6 +14868,7 @@ F:	include/dt-bindings/
 
 OPENCOMPUTE PTP CLOCK DRIVER
 M:	Jonathan Lemon <jonathan.lemon@gmail.com>
+M:	Vadim Fedorenko <vadfed@fb.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/ptp/ptp_ocp.c