ARM: dts: aspeed: everest: Add pcie cable card indicator leds

These are leds on the IBM proprietary PCIE cards called cable cards.
Cable cards have 2 ports on them and each port has an indicator led.
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210607031259.475020-7-joel@jms.id.au