MAINTAINERS: Update after GEHC spin-off

Update our email addresses, from @ge.com to @gehealthcare.com, after GE
HealthCare was spun-off from GE.

Remove Antti, who no longer works on the project.

Signed-off-by: Ian Ray <ian.ray@gehealthcare.com>
diff --git a/board/ge/bx50v3/MAINTAINERS b/board/ge/bx50v3/MAINTAINERS
index c165048..53a8d88 100644
--- a/board/ge/bx50v3/MAINTAINERS
+++ b/board/ge/bx50v3/MAINTAINERS
@@ -1,5 +1,5 @@
 GE BX50V3 BOARD
-M:	Ian Ray <ian.ray@ge.com>
+M:	Ian Ray <ian.ray@gehealthcare.com>
 M:	Martyn Welch <martyn.welch@collabora.com>
 S:	Maintained
 F:	arch/arm/dts/imx6q-b450v3.dts