boards: nxp: mimxrt1050_evk: fix reference to A0 silicon on EVK

RT1050 EVK rev A boards (with rev A silicon) are not well supported by
Zephyr. Update the documentation page to remove the reference to A0
silicon, as the page describes details specific to the RT1050 EVKB with
rev B silicon.

Signed-off-by: Daniel DeGrasse <[email protected]>

Author: danieldegrasse

boards/nxp/mimxrt1050_evk/doc/index.rst

@@ -17,9 +17,6 @@ and camera sensors. As with other i.MX processors, i.MX RT1050 also has rich
 audio and video features, including LCD display, basic 2D graphics, camera
 interface, SPDIF, and I2S audio interface.
 
-The following document refers to the discontinued MIMXRT1050-EVK board. For the
-MIMXRT1050-EVKB board, refer to `Board Revisions`_ section.
-
 .. image:: mimxrt1050_evk.jpg
    :align: center
    :alt: MIMXRT1050-EVK