ARM: dts: qcom: add pseudo random number generator on the IPQ4019

This architecture has a pseudo random number generator
supported by the existing "qcom,prng" binding.

rngtest: bits received from input: 5795960032
rngtest: FIPS 140-2 successes: 289591
rngtest: FIPS 140-2 failures: 207
rngtest: FIPS 140-2(2001-10-10) Monobit: 25
rngtest: FIPS 140-2(2001-10-10) Poker: 28
rngtest: FIPS 140-2(2001-10-10) Runs: 91
rngtest: FIPS 140-2(2001-10-10) Long run: 67
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=244; avg=46122; max=3906250)Kibits/s
rngtest: FIPS tests speed: (min=1.327; avg=20.966; max=26.345)Mibits/s
rngtest: Program run time: 386965827 microseconds

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Andy Gross <andy.gross@linaro.org>