MAINTAINERS: rectify entries for ARM DRM DRIVERS after dt conversion

The three commits:

  36fd2a65 ("dt-bindings: display: convert Arm HDLCD to DT schema")
  0f698350 ("dt-bindings: display: convert Arm Komeda to DT schema")
  2c8b082a

 ("dt-bindings: display: convert Arm Mali-DP to DT schema")

convert the arm display dt-bindings, arm,*.txt to arm,*.yaml, but miss to
adjust its reference in MAINTAINERS.

Hence, ./scripts/get_maintainer.pl --self-test=patterns complains about
broken references.

Repair these file references in ARM HDLCD DRM DRIVER, ARM KOMEDA DRM-KMS
DRIVER and ARM MALI-DP DRM DRIVER.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220601041746.22986-1-lukas.bulwahn@gmail.com