ARM: Kconfig: Mention Renesas ARM SoCs instead of SH-Mobile

Only the SH-Mobile product name is mentioned in the Kconfig descriptions
and help texts. This makes it difficult for external engineers working
on other Renesas platforms to find upstream platform support as the
combination of the SH-Mobile name and using the product number proved an
effective method of concealment.

Replace the "SH-Mobile" name with "Renesas ARM SoCs" in all the related
descriptions, help texts and comments.

Reported-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>