soc: ti: wkup_m3_ipc: Drop wait from wkup_m3_rproc_boot_thread

The function wkup_m3_rproc_boot_thread waits for asynchronous
firmware loading to parse the resource table before calling
rproc_boot(). However, as the resource table parsing has been
moved to rproc_boot(), there's no need to wait for the
asynchronous firmware loading completion.  So, drop this.

CC: Dave Gerlach <d-gerlach@ti.com>
CC: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Sarangdhar Joshi <spjoshi@codeaurora.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>