net: cnss_prealloc: Add prealloc memory for dual WiFi device

The dual WiFi device has two wlan modules one is interfaced with PCIE bus
and other one is interfaced with SDIO bus. Both the wlan module has
shared common pre-allocated memory pool for its internal usage and
release pre allocated memory back to pre-allocated pool.

Currently the pre-alloc memory pool can accommodate the pre-allocated
memory for single wlan module. Due to unavailability of pre-alloc memory
and dynamic memory allocation failure(system memory highly fragmented)
for the dual WiFi device we observe wlan functionality issue(driver load,
scanning and connection failure) where the wlan driver request for
physical contiguous memory size more than one page.

Add  minimum memory chunks to pre alloc memory pool which can satisfy
the memory request by the wlan driver for huge physical contiguous memory.

Change-Id: I147c00fab24d61c20fc06b7a5cbefdd0a985822b
CRs-Fixed: 1023989
Signed-off-by: Anand Kumar <anandkumar@codeaurora.org>