kernel/resource: Introduce request_mem_region_muxed()

kernel/resource: Introduce request_mem_region_muxed()

commit 27c196c7b73cb70bbed3a9df46563bab60e63415 upstream.

Support for requesting muxed memory region is implemented but not
currently callable as a macro. Add the request muxed memory
region macro.

MMIO memory accesses can be synchronized using request_mem_region() which
is already available. This call will return failure if the resource is
busy. The 'muxed' version of this macro will handle a busy resource by
using a wait queue to retry until the resource is available.

Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Cc: Mario Limonciello <Mario.Limonciello@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>