esp_ws2812.h exposes esp_ws2812_setup() with a struct rmt_dev_s * argument
but did not include esp_rmt.h directly.
After guarding the LIRC board registration path with CONFIG_DRIVERS_RC,
non-RC ESP configs no longer pulled in the RMT type indirectly and CI
started failing with an incomplete struct rmt_dev_s declaration.
Include esp_rmt.h in the Xtensa and RISC-V ws2812 headers.
Signed-off-by: Piyush Patle <piyushpatle228@gmail.com>