fix(linux): Add note to help format eMMC root partition

The examples listed in MMC-SD assume there are two partitions in
eMMC UDA, but the eMMC boot guide should only have one for the rootfs.
Add a note in eMMC boot guide to replace '/dev/mmcblk0p2' with
'/dev/mmcblk0p1' since examples in eMMC boot guide refer to those in
MMC-SD.

Signed-off-by: Judith Mendez <jm@ti.com>

Author: jmenti

source/linux/How_to_Guides/Target/How_to_emmc_boot.rst

@@ -226,9 +226,11 @@ possible to format a partition to ext4 in U-Boot, so the recommended process is
 an SD card with TI SDK image, boot the device with SD card boot to Linux kernel prompt,
 and prepare eMMC UDA from Linux.
 
+Note that in the following examples the "root" partition is the second disk partition, in our
+case, "root" will be the first partition so replace :file:`/dev/mmcblk0p2` with :file:`/dev/mmcblk0p1`.
 First create a "root" partition to flash the rootfs as shown :ref:`here <mmc-create-root-partition-emmc-linux>`.
 The new disk partition should be formatted as ext4 type as shown :ref:`here <mmc-format-partition-ext4>`.
-Mount the new partition and flash the rootfs as shown  :ref:`here <mmc-flash-emmc-uda-root>`.
+Mount the new partition and flash the rootfs as shown :ref:`here <mmc-flash-emmc-uda-root>`.
 The Linux kernel :file:`Image` and DT file are expected to be in the /boot folder of the
 "root" partition in order for u-boot to find and load them.