Change to follow the Kconfig style guide. This patch fixes to use tab
rather than space to indent, while help text is indented an additional
two spaces.

Link: https://lore.kernel.org/r/20220815025006.48167-1-mie@igel.co.jp
Fixes: e35f56bb ("PCI: endpoint: Support NTB transfer between RC and EP")
Signed-off-by: NShunsuke Mie <mie@igel.co.jp>
Signed-off-by: NLorenzo Pieralisi <lpieralisi@kernel.org>