ARM: dts: r8a7793: consistently use single space after =

Consistently use a single space after a =.

This patch removes instances where a tab is used instead.  It also avoids
running over 80 columns in width in one of the lines where whitespace is
updated.

This patch should not introduce any functional change.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>