The igt_check_drm_format_min_pitch() function had a lot of
KUNIT_EXPECT_* calls, all of which ended up allocating and initializing
various test assertion structures on the stack.

This behavior was producing -Wframe-larger-than warnings on PowerPC, i386,
and MIPS architectures, such as:

drivers/gpu/drm/tests/drm_format_test.c: In function 'igt_check_drm_format_min_pitch':
drivers/gpu/drm/tests/drm_format_test.c:271:1: error: the frame size of
3712 bytes is larger than 2048 bytes

So, the igt_check_drm_format_min_pitch() test case was split into three
smaller functions: one testing single plane formats, one testing
multi-planar formats, and the other testing tiled formats.

Fixes: 0421bb0b ("drm: selftest: convert drm_format selftest to KUnit")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Maíra Canal <mairacanal@riseup.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220729124726.748221-1-mairacanal@riseup.net