MAINTAINERS: add entry for DCP-based trusted keys

This covers trusted keys backed by NXP's DCP (Data Co-Processor) chip
found in smaller i.MX SoCs.

Signed-off-by: David Gstir <[e-mail]>
Acked-by: Jarkko Sakkinen <[e-mail]>
Signed-off-by: Jarkko Sakkinen <[e-mail]>

MAINTAINERS

···
 F:	include/keys/trusted_caam.h
 F:	security/keys/trusted-keys/trusted_caam.c
 
+KEYS-TRUSTED-DCP
+M:	David Gstir <[e-mail]>
+R:	sigma star Kernel Team <[e-mail]>
+L:	[e-mail]
+L:	[e-mail]
+S:	Supported
+F:	include/keys/trusted_dcp.h
+F:	security/keys/trusted-keys/trusted_dcp.c
+
 KEYS-TRUSTED-TEE
 M:	Sumit Garg <[e-mail]>
 L:	[e-mail]