ARM: dts: msm: Disable UART_4 on SA515M CCARD boards

Disable this UART port on CCARD since it is not
being used and it conflicts with other devices.

Change-Id: I66cac770eb63944f13cce07bda52dda2abee1921
Signed-off-by: Gustavo Solaira <gustavos@codeaurora.org>