MAINTAINERS: Add Jan Petrous as the NXP S32G/R DWMAC driver maintainer

Add myself as NXP S32G/R DWMAC Ethernet driver maintainer.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jan Petrous (OSS) <jan.petrous@oss.nxp.com>
Link: https://patch.msgid.link/20241205-upstream_s32cc_gmac-v8-15-ec1d180df815@oss.nxp.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>