serial: msm_geni_serial: Fix deadlock scenario with rx_lock

In one core msm_geni_serial driver acquiring port->rx_lock in
stop_rx_sequencer function in process context by calling handle_rx_dma_xfer
and this process is preempted becz of core interrupt is
fired on same core and then same lock is trying to acquire
from interrupt context. This is resulting in deadlock issue.

Below are the core call stack of deadlock.

Core 0 LR: _raw_spin_lock[jt]+40 <ffffffe973336e14>
[<ffffffe971f1df5c>] handle_rx_dma_xfer+0x44
[<ffffffe971f1ec70>] msm_geni_serial_handle_isr+0x6fc
[<ffffffe971f1f6ec>] msm_geni_serial_isr+0x40
[<ffffffe9721634a8>] __handle_irq_event_percpu+0x158
[<ffffffe9721637d8>] handle_irq_event+0x60
[<ffffffe972169548>] handle_fasteoi_irq+0x128
[<ffffffe972162364>] __handle_domain_irq+0xa0
[<ffffffe971e81b64>] gic_handle_irq$7f58c51dd0f0d487d89dbb027abc57c5+0xb8
[<ffffffe971e83f84>] el1_irq+0x104
[<ffffffe971f1df68>] handle_rx_dma_xfer+0x50
[<ffffffe971f1d9ac>] stop_rx_sequencer+0x118
[<ffffffe971f20f94>] msm_geni_serial_set_termios+0x114
[<ffffffe9726dbd30>] uart_change_speed+0x58
[<ffffffe9726ddf40>] uart_set_termios$ecf561cdccc9a487f79dc2d4825d91c7+0xd4
[<ffffffe9726d033c>] tty_set_termios[jt]+0x1c0
[<ffffffe9726d0c2c>] set_termios+0x124
[<ffffffe9726d0894>] tty_mode_ioctl+0x468
[<ffffffe9726d117c>] n_tty_ioctl_helper+0xac
[<ffffffe9726cc498>] n_tty_ioctl$31461d4e731178606d28313f43c714a4[jt]+0x318
[<ffffffe9726c80cc>] tty_ioctl+0x37c
[<ffffffe9723185fc>] do_vfs_ioctl+0x384
[<ffffffe97231923c>] __arm64_sys_ioctl+0x78
[<ffffffe9720be588>] el0_svc_common[jt]+0xd8
[<ffffffe9720be4c8>] el0_svc_handler+0x68
[<ffffffe971e84e88>] ret_to_user[jt]+0x0.

Change-Id: I7e1392cd82a93b1da6b19f05dbe67b66d46193f1
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>