board-8960-gpiomux: Correct Primary UART GPIOs suspend configuration

Currently Primary UART GPIos (93, 94, 95, 96) are having suspend
configuration where functional mode is set as 2 (UART Mode). These
GPIOs are required to be in GPIO mode when those are not used for
UART functionality. Hence correct these GPIOs suspend configuration
by changing functional mode from 2 (UART Mode ) to 0 ( GPIO Mode ).

CRs-Fixed: 467671
Change-Id: I98b101a665a0d6398007be7f0b13007cc71cffc3
Signed-off-by: Mayank Rana <mrana@codeaurora.org>