spl: kconfig: separate sysreset and firmware drivers from misc

This adds separate kconfig options for drivers/sysreset and
drivers/firmware.

Up to now, CONFIG_SPL_DRIVERS_MISC_SUPPORT added drivers/misc to SPL
build but also added drivers/firmware and drivers/sysreset at the same
time.

Since that is confusing, this patch uses CONFIG_SPL_SYSRESET for
drivers/sysreset and adds CONFIG_SPL_FIRMWARE for
drivers/firmware (and accordingly for the TPL options).

CONFIG_SPL_DRIVERS_MISC_SUPPORT stays for including drivers/misc into
the SPL build (and accordingly for TPL) since there are boards using
non-DM (non UCLASS_MISC) files from drivers/misc. Such boards don't
have CONFIG_SPL_MISC enabled, so cannot use this to include
drivers/misc into the SPL build.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
diff --git a/configs/kylin-rk3036_defconfig b/configs/kylin-rk3036_defconfig
index 921af0d..a76ae9d 100644
--- a/configs/kylin-rk3036_defconfig
+++ b/configs/kylin-rk3036_defconfig
@@ -49,6 +49,7 @@
 CONFIG_PINCTRL=y
 CONFIG_DM_REGULATOR_FIXED=y
 # CONFIG_SPL_DM_SERIAL is not set
+# CONFIG_SPL_SYSRESET is not set
 CONFIG_DEBUG_UART_SHIFT=2
 CONFIG_SYSRESET=y
 CONFIG_USB=y