MAINTAINERS: Update Lukasz Luba's email address

Update Lukasz Luba's email address to @arm.com in MAINTAINERS and map it
correctly in .mailmap file.
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

.mailmap

@@ -152,6 +152,7 @@ Linus Lüssing <linus.luessing@c0d3.blue> <linus.luessing@web.de>
 Linus Lüssing <linus.luessing@c0d3.blue> <linus.luessing@ascom.ch>
 Li Yang <leoyang.li@nxp.com> <leo@zh-kernel.org>
 Li Yang <leoyang.li@nxp.com> <leoli@freescale.com>
+Lukasz Luba <lukasz.luba@arm.com> <l.luba@partner.samsung.com>
 Maciej W. Rozycki <macro@mips.com> <macro@imgtec.com>
 Marc Zyngier <maz@kernel.org> <marc.zyngier@arm.com>
 Marcin Nowakowski <marcin.nowakowski@mips.com> <marcin.nowakowski@imgtec.com>

MAINTAINERS

@@ -4999,7 +4999,7 @@ F:	include/linux/dma-mapping.h
 F:	include/linux/dma-noncoherent.h
 
 DMC FREQUENCY DRIVER FOR SAMSUNG EXYNOS5422
-M:	Lukasz Luba <l.luba@partner.samsung.com>
+M:	Lukasz Luba <lukasz.luba@arm.com>
 L:	linux-pm@vger.kernel.org
 L:	linux-samsung-soc@vger.kernel.org
 S:	Maintained