test: dm: Fix wrong aliases property names

test: dm: Fix wrong aliases property names

After importing v4.17-rc1 Linux commit 9130ba884640 ("scripts/dtc:
Update to upstream version v1.4.6-9-gaadd0b65c987"), sandbox build
reports below warnings:

arch/sandbox/dts/test.dtb: Warning (alias_paths): /aliases: aliases property name must include only lowercase and '-'
arch/sandbox/dts/test.dtb: Warning (alias_paths): /aliases: aliases property name must include only lowercase and '-'
arch/sandbox/dts/test.dtb: Warning (alias_paths): /aliases: aliases property name must include only lowercase and '-'
arch/sandbox/dts/test.dtb: Warning (alias_paths): /aliases: aliases property name must include only lowercase and '-'

Silent them by applying the 's/_/-/' substitution in the names of the
'fdt_dummy0', 'fdt_dummy1', 'fdt_dummy2', 'fdt_dummy3' properties.

Similar DTC warnings have been recently fixed in Linux kernel, e.g. via
v4.17-rc1 commit d366c30d19f4 ("ARM: dts: STi: Fix aliases property name
for STi boards").

If done alone, the DTS update generates a failure of the
`ut dm fdt_translation` unit test in sandbox environment as seen below:

$ ./u-boot -d arch/sandbox/dts/test.dtb
---<-snip->---
=> ut dm fdt_translation
Test: dm_test_fdt_translation: test-fdt.c
test/dm/test-fdt.c:444, dm_test_fdt_translation(): 0 == uclass_find_device_by_seq(UCLASS_TEST_DUMMY, 0, 1, &dev): Expected 0, got -19
Test: dm_test_fdt_translation: test-fdt.c (flat tree)
test/dm/test-fdt.c:444, dm_test_fdt_translation(): 0 == uclass_find_device_by_seq(UCLASS_TEST_DUMMY, 0, 1, &dev): Expected 0, got -19
Failures: 2
---<-snip->---

Fix this issue in place, by updating the "name" string in the
UCLASS_DRIVER(fdt_dummy) definition, so that it matches the newly
updated aliases properties. After that, the test passes:

$ ./u-boot -d arch/sandbox/dts/test.dtb
---<-snip->---
=> ut dm fdt_translation
Test: dm_test_fdt_translation: test-fdt.c
Test: dm_test_fdt_translation: test-fdt.c (flat tree)
Failures: 0
---<-snip->---

Fixes: e8d5291824e2 ("core: ofnode: Fix translation for #size-cells == 0")
Reported-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Simon Glass <sjg@chromium.org>