gpio: generic: Revert to old error handling in bgpio_map
gpio: generic: Revert to old error handling in bgpio_map

Returning an error instead of NULL in bgpio_map if
platform_get_resource_byname does not find a resource was introduced with
commit cf3f2a2c8bae ("gpio: generic: improve error handling in bgpio_map").
This results in several qemu runtime failures with default and non-default
configurations, if attempts are made to boot from mmcblk0. Examples for
failures with multi_v7_defconfig are

Machine: vexpress-a9	dtb: vexpress-v2p-ca9
Machine: vexpress-a15	dtb: vexpress-v2p-ca15-tc1

Crash:

VFS: Cannot open root device "mmcblk0" or unknown-block(0,0): error -6
Please append a correct "root=" boot option; here are the available partitions:
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Looking into the code, always returning an error if bgpio_map fails
does not appear to make much sense, since the code in bgpio_setup_io
specifically supports some of the resources to be NULL.

Fixes: cf3f2a2c8bae ("gpio: generic: improve error handling in bgpio_map")
Cc: Heiner Kallweit <688f3b22cb68c85c90f972acb3bbdba2c5ca2ae1@gmail.com>
Signed-off-by: Guenter Roeck <ba324ca7b1c77fc20bb970d5aff6eea9377918a5@roeck-us.net>
Signed-off-by: Linus Walleij <9cd9d802d23c0ed5e224beabf4ae4a5c478746ef@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs