PCI: endpoint: Fix Kconfig indent style

PCI: endpoint: Fix Kconfig indent style

[ Upstream commit 2759ddf7535d63381f9b9b1412e4c46e13ed773a ]

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: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
Signed-off-by: Shunsuke Mie <mie@igel.co.jp>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Stable-dep-of: 37587673cda9 ("PCI: endpoint: Fix a Kconfig prompt of vNTB driver")
Signed-off-by: Sasha Levin <sashal@kernel.org>