drivers/sysreset: group sysreset drivers

Create drivers/sysreset and move sysreset-uclass and all sysreset
drivers there.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/Kconfig b/drivers/Kconfig
index f6003a0..4f84469 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -68,6 +68,8 @@
 
 source "drivers/spmi/Kconfig"
 
+source "drivers/sysreset/Kconfig"
+
 source "drivers/thermal/Kconfig"
 
 source "drivers/timer/Kconfig"